Square Market sounds simple, but it may be very easy for Rajaram to get lost in the weeds here. Because e-commerce is as complicated as transaction processing, only in completely different ways. The ability to pull people down a sales funnel, to turn suspects into prospects, to qualify them, convince them, and then to have them sign on the line which is virtually dotted is no small trick. So Square, which as Fast Company learned recently is still trying to capitalize on the deal with Starbucks ( SBUX) it signed in January, is taking a big risk. What started out easy is getting complicated. What made Square special is at risk of getting lost. But that was always going to happen. Complexity is the price of success. At the time of publication, the author was long GOOG and YHOO.Follow @DanaBlankenhorThis article is commentary by an independent contributor, separate from TheStreet's regular news coverage.