"You have to see this!" was one of the messages sent out last year by Glide, the video messaging app that quickly climbed to the top of the app store charts. Consumers who received that SMS on their smartphone and clicked the link were immediately taken to Glide to download the app. However, those SMS messages were not sent from friend to friend but were auto-generated by the app itself and distributed to the new users' entire SMS address books. Some call this growth hacking, but others describe it as "app spam," and recent changes from Google suggest a clampdown is on its way. For more on this topic, check out this FierceDeveloper special report.
