Marketers talk a lot about " customer experience," but what does it really mean? And how do you measure it? An emerging trend is marketers' using attention metrics to hold themselves accountable for delivering the types of experiences that capture people's interest. Those metrics look beyond solely the quantity of visits or impressions and to the quality of those engagements and the depth to which content is consumed.

Twitter co-founder Ev Williams summed up this dilemma perfectly: "We literally say one company or service is bigger based on a single number—specifically, number of people who have used it in the last 30 days. Even without getting into how use is defined, this is dumb."

Attention metrics help gauge the quality of the online experience—websites, lookbooks, landing pages, product campaigns, etc.—by measuring the ways which people interact with it.

Here are some recent stats about consumer attention and suggestions for measuring it.

Consumers are online on an increasing array of devices

1. A total of 52% of Web traffic to retail sites currently comes via smartphones and tablets, according to a recent report from IMRG Capgemini.

2. Over a third (36%) of online sales are now completed on a smartphone or tablet device.

3. That figure rises to 40% for clothing and apparel merchants.

Yet consumers are rewarding only the most trusted sites with their precious attention

4. A total of 41% of people feel overwhelmed by the wealth of choice on the Web, which makes it hard for them to make purchase decisions.

5. Some 33% feel there is so much information on the Internet that it is hard for them to find what they are looking for when shopping online.

And that attention online is getting shorter and shorter

6. People have a diminishing attention span—from an average of 12 seconds in 2000 to eight seconds today (goldfish have an attention span of nine seconds), according to a recent long-range study by Microsoft.

7. Moreover, "50% of websites get just 15 seconds of attention," states Tony Haile, CEO of Chartbeat.

Securing customers' attention is one of the most critical factors to achieving a high marketing ROI. What's needed is a meaningful way to measure it. For retailers, the standard approach is to look at bounce rates, add-to-cart, cart abandonment and conversion, but these are increasingly less relevant.

8. Initial impressions are really important, yet the industry average for bounce rates to retail websites is 30%.

9. Add-to-cart rates indicate how successful you are at supporting the user by displaying the right content in the right way. The average add-to-cart rate is 8% of visitors to any given retail site.

10. The average cart abandonment rate is 68.53%, according to a study by the Baymard Institute. That's more than two-thirds of consumers who fall at the last hurdle of the user journey.

11. Just 3% of consumers that add something to their cart convert to a purchase.

These measures of basic engagement also indicate what needs improvement, but what's needed are deeper insights.

There are three areas of attention to look at.

Time spent. How long does a consumer spend on your digital experience? This metric should examine not just whether consumers are visiting but also how long they are staying. The first 10 seconds are critical... How does that figure drop away over time?

12. The average time spent on an e-commerce website is 3 minutes, 49 seconds. The average time spent on a travel website is 4 minutes, 35 seconds, and the average time spent on a retail website is 3 minutes, 35 seconds, according to Wolfgang Digital's Benchmarking KPI Study of 56 million websites.

Actions. How are consumers engaging with your experiences? Are they staying in just one spot or moving around your site? This requires measuring what Upworthy refers to as "attention minutes," which look at a wide range of signals (video playing, mouse movements, scrolling, and more) to determine the depth to which content is being consumed.

13. Against this measure of attention, Upworthy counts more than 7 million attention minutes on its site per day. That’s more than 13 years of attention, every day.

Reactions. What did consumers think about the experience? Did it reflect positively or negatively on your brand? Are they brand advocates or a new public critics? Reactions help marketers measure positive or negative attention for their brand through social listening tools.

14. One recent report on 60 leading retail brands by social listening firm Brandwatch suggests that retailers are not listening and responding to their audience enough. Some 89% of consumers' comments are left unanswered.

15. On Twitter, these brands are successfully drawing a high volume of conversation yet only responding to 4.9% of the incoming chatter.

Taken together, looking at time spent, action, and reaction metrics provides a more relevant way to measure attention and gain critical focus points for improvement.

Online marketers should be aiming for a design that seamlessly takes the user where they want them to go. That means creating a journey that keeps customers immersed in a rich experience of related content or products, and combining that experience with intuitive design elements, such as a "shop the look" or a "buy now" button displayed during the first moments of a consumer's website visit.

The more time consumers spend on your site, softened, wowed, and rewarded by a great creative experience, the more likely they are to move effortlessly to the cart and the checkout. Having the right quality of measured insights along every step of this path to purchase lets marketers rapidly fill any gaps and enable customers to make easier purchase decisions.