I have seen this coming for a while too, It's a topic I discuss all the time with ... While bigger users seem to still be resorting to bid votes, users with smaller stakes seem to be going for community bots, those that you can delegate to and recieve a daily upvote based on delegation or you pay for a monthly subscription and secure an upvote a day for your posts for some visibility.
RE: The end of an era - the last truly profitable vote-buying service dries up.