Nothing wrong with Bumping unless
1. The topic is old as hell like 2010,2011
2. You only say one word like Lol, Yes, Ok, Or my favorite sentence "I'm from the future! Derp"
3. You're a whore for post counts.
4. You reply to someone 2-3 years ago (i've seen this recently happen)
Bumping is ok if you are updating a topic you are trying to revive or... don't bump at all just start fresh.