I just finished attempting this method to increase my Dropbox space. It worked, just not as well as I had hoped. If you don’t know what Dropbox is, it’s a tool to automatically sync files across all of your devices; think Apple iCloud, but better. Feel free to sign up using my referral link: http://db.tt/oShp9Gu :)
Basically, Dropbox gives you a referral link that you can share via email and social networks. Every time someone signs up and then installs the program on their computer using your personal link, you get a space increase on your account (250MB or 500MB if you register as a student). This method walks you through using Google AdWords to advertise your link on Google for people who are searching for Dropbox.
I happened to have a $100 credit from using Google Analytics so I used that to fund my ad. Over 5 days I was able to claim 5GB of the possible 16GB of referral space. My guess is that there were many people doing the same as me and so that’s why I wasn’t able to max out my space as the author of the post had. I’m sure the keywords I used/didn’t use had something to do with it as well. I used the ones suggested in the article, then used AdWords’ keyword tool to generate more, and after a couple days Google suggested some more as well.
If I hadn’t had the credit, it would have cost me $100 for 5GB of space. That is a permanent increase but not really worth it. This will probably be better in a year after everyone is done attempting it.
EDIT: I forgot to mention that about half of the people that signed up using my link didn’t actually install the program on their computer. Once/if they do that I will get more space increases.
EDIT 2: Looks like there’s some of these ads on my Google sidebar ad haha.