According to Forrester Research, U.S. e-commerce sales are expected to hit $370 billion by 2017 – that’s 10 percent of retail sales. These are some pretty staggering figures that brands and their CMOs cannot afford to ignore. More than anything, it’s a harsh reminder of just how much revenue they stand to lose if they get the online experience wrong.

Consumers today are finicky and want what they want, now. Some place the highest premium on loyalty and trust in a brand or product. Others, bound by the unstable economy, prefer deep discounts and bargains. And then there’s the ever-growing population of consumers who are always connected and always on, thanks to their smartphones and tablets. As different as consumers are, they all want to feel like the brands and products they use are tailored specifically for them. By providing personalized, relevant and unique content in line with consumers’ likes and dislikes, purchase behaviors and demographic profiles, they’ll increase eyeballs to their online or mobile sites, boost traffic and, most important, drive short-term and long-term sales. Here are five reasons why CMOs cannot ignore the power of personalization any longer, or they may soon be shutting their doors.

Make data your best friend.

It’s unfortunate, but a lot of brands these days are still guessing their way through their website design and e-commerce strategy. As smart and creative as most brands think they are, the numbers don’t lie. Data can be one of the most inexpensive and smart listening tools a brand can have in its arsenal. I can’t stress enough the importance of brands analyzing what works and what’s missing the mark with all of their design changes through A/B and multivariate testing. That kind of data is more apt to deliver real insights into who their audience is, what types of content and information they want, and where they are making those purchases. All of those learnings, in turn, can result in increased clicks, higher conversion rates, more revenue and happier customers.

Reach the right audience.

What is the demographic profile of your primary customers? Are a significant portion of your online customers also smartphone and tablet owners? Does product pricing influence the purchase decisions of your customers? The identity of your customers, their demographic profiles, what types of information they value as well as when and where they are making purchases are all insights that can help you reach the right audience at the right time with the right content – whether it’s in the form of emails, product recommendations or social promotions. So doesn’t it make sense to test and optimize your website to reach the right audience at the right time with the right content?

Be relevant, unique and indispensable.

One of the best ways to attract and retain customers is to make your brand and products so relevant, unique and indispensable that they would suffer if they went elsewhere. According to Forrester’s 2012 North American Brand Performance Study, being indispensable commands greater preference, and that means a higher likelihood that customers are going to keep spending their hard-earned dollars with your brand across multiple channels. One way to satisfy consumers’ high standards is to make product recommendations as personal and strategic as possible. Showing the right products in the best way on the right pages can result in higher site traffic, longer engagement times on landing pages and more sales. That’s a win-win for both brands and consumers.

Smartphones and tablets drive e-commerce growth.

If you think investing the time, resources and dollars into testing and optimizing your site for smartphones and tablets isn’t that urgent, think again. According to eMarketer, 15 percent of online retail sales this year will take place via mobile devices, which is up from 11 percent in 2012. Overall, U.S. retail m-commerce sales are predicted to reach nearly $39 billion in 2013, up 56.5 percent from 2012 and almost triple the amount spent in 2011.

But not every smartphone and tablet is the same; each device type, model and platform comes with its own unique set of features and functions. Failing to optimize and personalize your website for the smaller screen could very well mean the difference between being profitable and going bankrupt.

Forge meaningful social relationships.

Social media has forever changed the way we use the Internet and consume information. Once considered to be a new “fad,” social media is now an integral part of consumers’ daily lives. A study by Forrester Research found that 45 percent of people on social networks have interacted with a brand through social media over the previous three months. It’s especially interesting to see that 71 percent of online adults are accessing social networking sites at least monthly.

Despite how popular and “cool” it’s become for brands to have a social presence on sites like Facebook, Twitter, Instagram and Pinterest, many have done so without any real strategy or testing behind them. How often do you hear brands bragging about reaching 1 million fans or “likes” on their Facebook page? But these metrics aren’t tied in any way to ROI and sales. Incorporating social data into your overall personalization program can convert those actions into leads and revenue. Isn’t that what really matters to your business?

If the $42.3 billion spent online this past holiday season has taught retailers anything, it’s that capturing customers—and their dollars—online is crucial.

But online is a big place. And mobile, which can seem like an entirely different universe, looms ever larger. So where to even start if you haven’t yet…started? And who should lead the charge?

The modern day merchant must have an intimate understanding of the importance of online and mobile commerce, access to a vast array of customer data, and a strategy for transforming this analytical data into winning online experiences.

In all cases, the goal is to attract and retain both new and returning customers. Whether online novices or experts, business leaders crave insight on how to accomplish this. The question is: who inside the company can embody these traits and help the CEO rule the roost? That responsibility should belong to the chief marketing officer.

A CMO should be somebody who uniquely understands marketing, merchandising, data, analytics and web design, and who can also maintain a creative, innovative organizational structure. IT tends to lean too heavily toward data for data’s sake, while Sales too often relies on revenue and relationships.

Placing the CMO in charge allows for the best of both worlds. Armed with the science of data analysis and the art of consumer engagement, the CMO is well positioned to emulate merchant princes of old and join the ranks of retail royalty. A good CMO can nurture a culture of testing, measuring and learning instead of depending on guesswork and subjectivity, as well as reach out to those on the front lines of customer interactions to figure out what those customers want. The ambitious CMO knows that their company site must be more engaging than the competitions’, as well as a place that customers trust, valuing the available products, services and information on offer. It also needs to be a reliable gateway to actions that grow sales beyond the initial purchase, such as cross-selling and upselling.

What’s the best way to make all this happen? One word: data.

Data is crucial to online retail. It comes in many different forms, the main type being the individual behaviors of current site visitors: which search term or webpage brought them over, what time of day and day of the week they’re most likely to stop by, what recent purchases they’ve already made onsite, what pages they visit and what product categories most interest them. All this pertinent info helps define what the “best content” is for each specific viewer. Other types include customer relationship management (CRM) data and social media data.

The aspiring CMO must then use this accumulated data to gain perspective on what customers want; analytical optimization and personalization tools will aid in this quest. Segmentation sifts through the data to find discrete groups of people with similar traits and/or interests, who can then be targeted and tested with relevant content based on site activity. Product recommendations and other offers are then provided based on what the various groups are most likely to purchase.

Product information tools give customers a deeper understanding of the product at hand—a 360-degree view of an article of clothing, or a close-up of various types of textured materials. User-generated content, like ratings, reviews or social media feedback, also aids and influences purchasing decisions. The savvy CMO uses all these methods to strike the delicate balance between intuition and analysis.

On the face of it, the idea of a rigorously testing and optimizing your ecommerce web site seems like a no-brainer.

After all, who would object to gathering hard data on exactly how customers move through your site, what happens on specific visits, and what unseen speed bumps and sticking points are hurting sales? Who wouldn’t want definitive answers to such questions?

Fact is, though, in many online marketing organizations, there is often surprisingly sharp resistance to technologies such as multivariate testing.

Sometimes, it’s simply because there’s some confusion about how multivariate testing actually works and what the benefits are. (“You’re going through all this to test the color of the ‘Buy Now” button? Really?”)

But the real problem usually is buried a little deeper. With hard testing comes the threat of upsetting or overturning some cherished beliefs, or disproving what people ‘know’ to be true. Marketing and creative teams have traditionally crafted websites around ‘established principles’ and ‘gut feel’ for what works. (What if that isn’t so? What if we’ve been dead wrong all this time?)

The IT people build the site a certain way because it’s simple and robust makes perfect sense in terms of data flow. (But what if that actually turns customers off? What if that makes shoppers bail out before buying?)  The notion of actually testing ingrained practices is a bit scary.  Who wants to have their worldview changed?

In other cases, there’s some reluctance to admitting there’s even a problem.  “We’re getting X% conversions. That’s the industry norm.  Nobody is complaining. Why bother?”

The best approach to getting buy-in for a testing strategy is to position it as less of a of a threat, and more of a way to ‘refine’ and direct the efforts of your creative, marketing and IT teams.  It’s a way to out-smart, out-maneuver, out-think your competitors; it’s not a way to beat up on what we’ve been doing.

Detail the pain, document the bad

First step:  point out the pain points on your site. Are visitors fleeing as soon as they arrive? Are they actually buying or just poking around?  Do they buy once, and disappear forever?

To make your case, use strong graphics, charts, video clips, whatever it takes. But make sure the visuals are backed up by solid data that will speak to your audience: You bounce rate, cart abandonment rate, search engagement and average order value. Make the pain and problems clear, and the idea of a testing program will be much easier to sell.

Add up the losses

Find a way to dramatize and quantify how much money you’re losing in the current situation.  Then show how much more money the company could be making if you could get hard data on exactly what’s working and what’s not working.

Bring up smart competitors, industry darlings

Peer pressure is another go-to tactic for getting reluctant executives to embrace change. Explain how other respected, successful organizations are leaping ahead by definitively testing what they’re doing. For examples, check business publications, LinkedIn, public case studies, blogs and so forth.

Nobody likes to be left behind — if stakeholders see other businesses are implementing test programs to their benefit, it’s more likely they’ll want to do the same. And if competition’s already ahead of the game, even better for you. (Although the alternative is that they’re not and you can beat them to the chase.)

Speak to IT on their terms

Your development teams may feel that site testing is unnecessary, especially if they’ve already evaluated usability and other qualitative factors. They may consider testing their domain, and not appreciate any input from the marketing department.

Address these concerns by speaking their language and giving them concrete information they can actually use in making development decisions. Don’t just have a verbal discussion — provide all those statistical facts in writing, in terminology they know and use. Point out that shifting the responsibility of site testing to marketing frees up IT time and manpower to work on other projects.

Relate it all to the brand

In a critical way, the e-commerce site is the final touch point, the ultimate ‘proof’ of the brand concept. Does the experience on the website match the brand promise? Does it reinforce and capitalize on all the branding efforts so far?  Is there something we can do better? Something in our web experience that is somehow compromising our brand?  Multivariate testing can quantify this very accurately.

“Just try it”

Finally, propose a trial run — a limited test, shown to a small percentage of page traffic. Be sure to track key data points like visitor stats, cost per conversion, and abandonment rates. Once the results are gathered, share them with various departments throughout the company. As more co-workers find out what’s going on, your potential support base will become even larger.