I thought it was like on Reddit, that it's less about you "liking" your own posts, but about giving it a better baseline automatically. On Reddit I think it matters quite a bit whether your post is 0 or 1 or higher early on, and when it languishes at 0 for a while it doesn't get picked up at all and drops off badly (even from new). So there it just does it automatically. Here I don't know how the algorithm works, maybe it matters maybe it doesn't.