Well, at least it better than nothing I think. I have just started with adsense program 4 months ago. The largest earning that I have recieve for a single click so far was $0.60. How I wish to earn more. But i think for starters like me, I would not expect a quick rich scheme. Anyway, I am sure you will be earning more later on.
If you think it's good, then it's good. Don't let people across the world tell you what's good and what's not!
Totally depends on the kind of site you got and how competitive those keywords are. I got some sites with an average of $1.50, then again i got some with an average $0.05
Firstly you have to plan your website with tags and search terms that are expensive for advertisers to buy at google. For instance if I run a socks business, then the term socks for sale or sale of socks, would be cheap for me to get a advert from google because they aint popular searches on the web. But if I sold holidays or insurance or information on adsense then these search terms get very expensive because of the popularity. It's like any business we all want to be number 1 in our field.
congrats for he 50 cents click! keep working at your site, i guess you got a good niche it's all about the niche! General content sites or entertainment/celeb/arcade etc gets low clicks! can you share your url!
The largest earning that I have recieve for a single click so far was $0.40,so you suppose to be happy with that earning.