I really should push it more often, but I really like to leave it up to the person if they want to donate or not. The decision to upgrade to a premium account comes with it's own benefits, seen here-
http://www.rme4x4.com/supporter.php
If someone wants a bigger PM box and all the extras that come with upgrading, then it's their call.
We used to push the monthly giveaways for premium members, but to be totally honest, it's not easy to approach the businesses that already support us, then ask for them to give us something that we can give away. With the current economy, most businesses are happy to make ends meet and we don't want to go around asking for free stuff.
Another thing worth mentioning, the more premium members we have, the easier it is for us to do fun things for our members, like print off stickers that we can give away, make up RME hoodies and shirts, etc.
So yeah... upgrade your RME account, good things will come of it!