Goodreads is still where I keep my shelf of Books Going to the Used Bookstore - at least until Booklikes has the ability for backup csv files. Today I added all my old Scott Adams Dilbert books - but I stopped buying his books in 2011 due to his online behavior. Here's a link that explains what happened - it's just the sort of author behavior we still see and use to make our purchase decisions now. I watched it occur on Metafilter, so I had a front seat.
Salon: Dilbert Creator's Ever Worsening PR Crisis, Apr 19, 2011
"...In Adams’ case, his exposure as a self-aggrandizing Internet troll who enjoys talking about himself in the third person brought no apologies or admissions of shame. He instead rationalized his stunt, pouting to the MetaFilter community, “I’m sorry I peed in your cesspool,” and adding, “smart people were on to me after the first post. That made it funnier.” Ah, yes, like when he posted, “I hate Adams for his success too,” when he really was that awesome, successful Scott Adams in disguise — hilarious! It’s like when Lois Lane gets all worked up about Superman, and Clark Kent is just standing around like, awww yeaaaah.
As MetaFilter moderator Cortex gently explained to the certified genius, "If you wanted to sign up for MetaFilter to defend your writing, that would have been fine. If you wanted to sign up for MetaFilter and be incognito as just another user, that’d be fine too. Doing both simultaneously isn’t; pretending to be a third party and high-fiving yourself by proxy is a pretty sketchy move and a serious violation of general community expectations about identity management around here.""
Short version: readers have been using online author behavior as a decision making factor in purchases for some time. This is nothing new. What is new - more authors are finding this out directly from readers.