How can one implement a hit count for AWS SimpleDb?

I have data in AWS SimpleDB and I want to know how popular it is. The client can be a website or a mobile device. I'd like some means of seeing just how popular it is. 100% accuracy is not especially important, so dropping a few here and there is acceptable.

How can I implement this?

(I was thinking that I might be able to do something with Google Analytics, but I don't know enough about this.)

Have you looked at your AWS account's Usage Reports? It has some pretty good, rough data. I don't think it will yield you a true hit counter but will tell you how many bytes various operations are consuming down to the hour/day.

I use GAE for some middleware stuff so if I needed a hit counter, that's where it would go. Don't know if you use a similar model. You could also of course write a hit counter into the database itself but that would be pretty inefficient.