Or it funnels available curation into specific places, away from others. For example, people like myself, who don't bother with "communities" are unable to get curated because we don't jump through hoops or play games. Some people think good content should speak for itself and not need gimmicks. It seems that "communities" (what the hell is alien art supposed to mean?) are just ways to ensure curation retains people who tow the line and do as they're told, and gets rid of independent thought.

Helps retention? Retention of what, people who use the right hashtags and apps? Or people with talent, skill, and effort to put into real content?