To bump or not to bump? That is the question

According to Wikipedia:

Bump (Internet), raising a thread's profile by returning it to the top of the list of active threads OR an abbreviation for "Bring up my post"

So how many of us think that bumping a post is a good thing?  It can be.  It can also be be used a a spamming tool.  There's nothing wrong with using the BUMP technique if you use it responsibly.

Responsible use of bumping:
To keep a quality post on the front page where it can be seen.
To jump start conversation on a dead post.

When you bump in this manner, you are bringing quality posts with good information or an important topic to the attention of others.  However if you are going to use bumping in this manner please post a comment.  Nothing is more annoying than looking at a topic and seeing the comment "bump"

Irresponsible use of bumping:
To get your ad to the top of the list. 

In some forums you see people who post an ad, and when you look at the comments you see that they are all from the author of the post and often are simply mindless statements or repeats of something already said in the post.

To knock off as many posts as possible leaving only your own.

I also see this a lot.  People who simply go through and bump all of their own ads and posts removing posts by anyone else from the front page. 

Bumping is one of the reasons I no longer invest my time at Twitter.  Many of those there do nothing but bump.  I see no reason which there should 10 posts from the same person on the front page.  Bumping in and of itself is neutral, how you choose to use the technique is either positive or negative.