To keep up, retailers have spent lots of money investing in shopping apps to offer customers the best possible mobile shopping experience. In a new BI Intelligence report, we look at how people's mobile shopping and buying behavior is shaping up, what consumers expect from a retailer's site and app, and what causes someone to transition out of an app and onto a site. 58% of mobile retail dollars going to the top 500 mobile retailers will come from the mobile web this year, with in-app purchases accounting for the rest, according to Internet Retailer. The mobile web is also how many consumers prefer to shop on a mobile device. 51% of shoppers were more interested in shopping on the mobile web over apps on their smartphones in 2013, according to Adobe data. The mobile browser, which is often a gateway to retailer sites, is an important first stop for shoppers using their smartphones in a store. Another 62% say they go directly to a retailer's mobile website, while only 21% use a retailer's mobile app in a store. 32% are still showing mobile users a desktop-optimized version of their website on mobile devices.