Wow, great minds think alike Brick. I noticed the credits yesterday and wondered the same thing. If you click on the credits you'll see a list of where you got and spent credits, as well as the top credit users.
Your's truly leads that category, so maybe it isn't a good thing
I did notice that I "spent credits" with one of my posts, but not sure why. Did I say something bad, or offend some people? Is this from some form of rating or liking a post? (The post was edited, did I remove somethig that previously earned me credits?)
What can I buy with my over 350 credits?