http://sn.1w6.org/file/lnxw48-20150226T160524-b6u75pj.html
Repeating vs voting: repeating expands the number of potential readers of a post by directly adding it to their stream (or elevating the post to the top of streams for those who've already got it); voting expands or contracts the number by indirect means using a popular posts algorithm. Voting is subject to all sorts of gaming, which is one of the reasons why sites like Reddit have to add so many ultra-powerful moderators.