An easy way to give myself some free publicity is to continually make small, essentially meaningless edits to my own questions/answers in order to bring them to the top of the list without actually contributing anything meaningful to the content of the thread. Should there be a limit in the amount of times you can edit your own post within, say, a 24 hour period?
If you try this, you will discover that such edits are rate-limited. Further, such activity would catch the attention of the moderators, which would lead to a discussion with you. Persisting in such activity would likely lead to a suspension. (I recognize, of course, that you would not do such a thing and are asking this question out of academic interest only.)
Note, also, that making more than ten edits to a single post (of yours) will cause it to become "community wiki", meaning that no further reputation will be earned. So if the goal is to keep bumping the same post to try to get more reputation, that'll stop working eventually.
Please do make significant, useful edits to old posts, yours or others'. The goal is to improve content. Bumping edited questions to the front page goes hand in hand with this, so please make those edits count -- if you're in there anyway to, say, add a link, see if there's any spelling or grammar or formatting or tagging that you should adjust while you're at it. And if there's a change you want to make that affects a lot of posts (like a retagging), please try to do it in small batches or, if that's not practical, bring it up on meta or in chat so we can figure out the least-disruptive way to do it.