I’ve been a Dropbox user since it first became available. While I have not completely used up my allocated space when I read this article on LifeHacker I had to give it a try.
How to Get 8GB+ Extra Dropbox Space for Free with Google AdWords
There is a bit of work to get this setup correctly but in just 2 days I’ve already gained an extra 4GB of free storage. You can get up to 8GB trough referrals. If you’re looking for more (free) storage on Dropbox It does not get much easier than this.