For the beginning, it's true that I don't like the fact that we use the same community ads again and again. According to that, I've decided that I'll downvote those 2014 community ads that I don't like, and upvote those that I do like. However, my votes obviously get reverted, both up-votes and down-votes, and it happens repeatedly.
One should be able to use his votes as he wants in the community ads thread. This is IMHO a bug.
PS: According to the comments here, the problem concerns upvotes, too. It seems that we trigger the serial-voting bot because most of the answers come from one person.