The idea is for the bump to work exactly as if you'd posted a reply, as far as the thread coming back into view. So if, for example, you edit your thread to include more cards, you could use the bump feature and that thread will come back to the first page of the thread listing page.
Now, after hearing feedback, I'm also working on a way so that it will show up in "What's new".
The idea is to simply get away from posts that say "bump", "ttt", or "up". Those types of posts do more harm than good from a search engine perspective, which doesn't mean much to most folks, but is important in helping new members find us.
I think once all the kinks are worked out everyone will be pleased with how it works.