Hacker News Reader

As far as I know, Dropbox is using S3, which has reduced its prices several times, so Dropbox should pass that saving onto its users just like AWS is.

Find one of the many "$100 of Adword credit free" coupons around, create an ad with your Dropbox referral link, sit back and watch your storage limit increase a couple times per hour.

I wouldn't recommend this unless you have specifically received one of these coupons at your email address. I used someone else's and my account was permanently suspended. Only after some negotiation was I able to make Google reverse the "permanent" suspension (a rarity, from what I have seen).

It wasn't hard to find one that I received myself. I've got coupons in magazines, hostgator, domain resellers... it shouldn't be too hard to come across one legitimately.

Setup an Adwords campaign and get some referrals. I think I got 5 or 6 referrals from this campaign: http://puu.sh/rimE