Shopping on a phone usually, well, sucks. It involves too much tapping on a tiny screen and much of the time the site that has what you need isn't optimized for mobile anyway.

Yet mobile e-commerce is steadily on the rise. In fact, last year it jumped 81 percent from 2011, totaling nearly $25 billion in sales. According to eMarketer in 2013 mobile retail purchases will grab a 15 percent share of all U.S. online retail sales, compared with 11 percent in 2012. By 2016 that number may reach 24 percent.

A mobile-optimized website is a necessity. In fact, Google is so concerned about websites that don't work well on mobile devices it recently warned it would demote sites that create headaches for smartphone users.

In addition to figuring out how to design for mobile, there's also the bigger question of how to lure impatient shoppers. A full 61 percent of people Google polled said they will quickly leave if they don't find what they want on a mobile site.

But how do you know what they want?

This Big Data Start-up Has Some Ideas

Tracking the desires and habits of people browsing the Web from a desktop is relatively easy because of all those cookies websites leave behind that allow companies to track a computer's IP address all around the Internet. If you've ever received a targeted ad about the car or swimsuit you were recently checking out online, now you know why.

Identifying how people use their mobile browser is also possible because companies leave cookies on mobile devices, which, by the way, have their own IP addresses, as well.

And one Silicon Valley start-up is doing some pretty interesting things with them.

CEO Raj De Datta and CTO Ashutosh Garg co-founded Mountain View, California-based BloomReach, a big data company with $41 million in funding that came out of stealth mode last year. The start-up developed what it calls a "Web Relevance Engine" that crawls the Internet looking at somewhere around 150 million web pages and billions of consumer interactions so as to anonymously profile individual IP addresses to figure out what the user behind it wants, likes, and shares. The technology, used by big brands such as Yahoo, Crate&Barrel, and Williams Sonoma, can then provide individual website visitors with customized landing pages.

In July BloomReach began offering companies the ability to do this across channels--meaning they can keep track of what individual customers are doing when they visit the merchant's website whether they're accessing it from a desktop computer or a mobile device. Called BloomReach Mobile, it works by analyzing multiple signals--things like time spent on a website, products clicked, bounce rates, and whether a user gravitates to sale items or specific brands and sizes. Then it finds signals that all appear to come from the same person. In addition, it couples cookies on a desktop browser with those on a mobile device.

"As a consumer engages with the brand's website and mobile site more frequently, the system learns and refines the match. In short, we don't need to know who you are to provide more relevant experiences across channels. If our data indicates that a consumer is not engaging with the personalized content across devices, our system will decouple the cookies," a BloomReach PR rep told me.

Currently Neiman Marcus, Deb Shops, and about eight other companies BloomReach wouldn't disclose are using its back-end big data services for optimizing mobile sites.

But What Will Consumers Think?

Christy Augustine, BloomReach head of mobile, gave me a GoToMeeting demo of the Deb Shops and Neiman Marcus mobile websites mirrored off her smartphone. She said there are two main use cases where the technology shines: killing time and when someone needs something right now.

She said the Deb Shops mobile site is an example of the former because its demographic is highly social. One BloomReach feature it employs is a "What's Hot" tab that calls up a mix of products that represent what customers are talking about on Facebook, Instagram, Pinterest, and other social networks.

The Neiman Marcus mobile site Augustine showed me did appear to have a certain stickiness to it, something that's important for impatient shoppers who have a specific item in mind--perhaps an outfit for an upcoming event.

For example, BloomReach can give a site visitor intuitive search suggestions after he or she taps only about three letters. Augustine typed in "lit" on the mobile site and received suggestions including what she was looking for, which was "little black dress."

She also tapped a "more like this" button which quickly called up only strapless dresses or only knee-length ones with sequins. A "just for you" feature syncs anything a person does at, so if you add a pair of earrings to your wish list on the desktop it's also there on mobile, as well.

But does it increase sales? BloomReach says David Cost, VP of e-commerce and digital marketing for Deb Shops, recently publicly stated at the retail industry conference eTail East that the company's conversion rate for shoppers who use BloomReach Mobile technologies is four times higher than it is for those who don't engage with the BloomReach tools on Deb Shops.

What About Privacy?

Privacy is a subject that inevitably rears its head alongside any discussion about tracking people's online activities.

BloomReach says it doesn't know who its customers' website visitors are--only how they behave online. The company does, however, automatically opt in users, though BloomReach says it offers multiple opportunities to opt out.

A Couple of Caveats

BloomReach does appear to make shopping with mobile devices easier. That said, it isn't cheap. The monthly minimum for companies that want to use its technology is around $10,000.

Also, not everyone reading this article can go to Neiman Marcus or Deb Shops on a smartphone and see the features I witnessed. That's because retailers control which kinds of phones have access to a BloomReach-powered site, sort of the same way that some apps can't be used on certain phones lacking the right operating system or support.

It's the same with mobile sites. Every device needs particular things from a mobile site for it to work properly. While you'd think companies want to offer a mobile-optimized site that performs well on every smartphone, doing so takes time. Instead, they typically start with the most-used devices and branch out from there. Once a company readies a mobile site for a new smartphone it can turn on BloomReach Mobile for that device.

If you want to see how it works and you're an iPhone user or own one of the top 10 most popular Android devices, visit or from your phone to see if it's a better shopping experience than usual. I'd love to get your feedback.