I’m currently attempting to max out my free Dropbox account by buying some AdWords that use my referral link. I’ll update this if I get any results.
Well I spent about $35 and got up to 11.5GB of space. I think I probably would have had better results without spending as much money, but I think some other people were trying to do the same thing at the time so we essentially got in a bidding war and drove the CPC up. I’ll probably try again to get to 16GB in a couple of months.