We made it really easy to use Feedburner to get analytics about who's reading your feed. Just burn your Posterous RSS feed and add the new Feedburner feed address to your site and you're off.

Grab the address from Feedburner:

Then add it to your site settings:

The next time you go to your site the feed icon will link to your Feedburner feed! You can find more setup instruction in our help section.