More than ever, social media channels are listening to the preferences and concerns of their users, and the result is a constant evolution of the apps and sites we love. This week, Twitter launched its homegrown alternative to Storify, and added promoted tweets to user profiles. Facebook targeted THOSE people on your newsfeed with a new service for parents, and Yik Yak founders discussed staying true to their niche following. Lastly, Snapchat execs addressed the concerns about privacy, bugs, and transparency in an exclusive and rare interview. Ch-ch-ch-changes!