Hi,
Yes, you get karma when others "applaud" you.
The stars accumulate as you post more - more posts put you in a higher group with more stars.
The groups are:
BeerSmith New Brewer - one star
BeerSmith Apprentice Brewer - two stars - 3-5 posts
BeerSmith Brewer - three stars - 25 posts
BeerSmith Master Brewer - four stars - 50 posts
BeerSmith Grandmaster Brewer - five stars - 100 posts
Cheers,
Brad