I think it's not efficient in reblogging your own posts. Just think about it. If you are reblogging - you are letting see thist post only to your followers. It's not appearing again in main steemit feed(new, active etc.) So - to the people who theoretically had seen your post already. And voted already.
RE: Wow, so I can reblog my own reblogs of any post made? Used for others though, it is better support than promoting.