With global ecommerce sales exploding at a rate of 16% year-over-year in Q2, reaching $49.8 billion, according to comScore, the industry is primed for growth.

Yesterday, the eTail East conference kicked off, drawing some 1,150 marketers, retailers and technology vendors to Philadelphia for the week. Last year, eTail Boston attracted 990 attendees, event organizers said.

This year, program tracks are broken down by topic, and range from mobile and tablet optimization to social engagement, advanced search and email marketing. When asked by AdExchanger what some of the key pain points brand clients are looking to solve, the overwhelming consensus among some of the early attendees was, “solve the problem of [cross-channel] attribution” and “justify ROI for spend” in ecommerce initiatives. In other words, marketers are looking for results they can measure and they’re using data to do it.

Here are some key marketing themes that are expected to emerge from this year’s ecommerce-centric show:

Measuring the cross-channel or “omnichannel” consumer: Rather than measuring only how consumers first come into contact with a brand on a channel basis, Jerry Joyce, an SVP with multichannel marketing services company Wiland Direct said the goal, increasingly, is to find the right formula to measure how individual consumers interact with a brand over time to optimize future messaging, ad placements or overall marketing spend, based on data determining how much that individual customer is worth to the brand. This echoes Forrester’s recent findings that “channel-specificity” is succumbing to an “omnichannel” strategy.

The hyper-targeted individual offer: Another key trend to watch, said Josh March, cofounder and CEO of enterprise social CRM company Conversocial, is the hyper-targeted offer. Specifically, he cited a platform like Sailthru, which is used by ecommerce site Fab.com, AOL and Thrillist to tailor personalized offers based on individual consumer profiles. Using what the company coined “smart data,” it’s applying the premise of “big data” or predictive analysis based on past behavior or purchase patterns to tailor email, site and in-app experiences to each consumer.

Taking the brick-and-mortar online: Offline and online data are converging, as companies like CVS Caremark aggressively go after digital means of driving in-store traffic. A key topic at eTail will be bridging the gap between data collected across physical and digital retail touch points. Beyond linking online activity to deliver a dynamic offer in-store, marketers will begin to tackle ways to do the reverse and tie in-store behaviors back to serve offers, ads, or recommended products through ecommerce experiences.