arsenische, you've accepted an ad on your service that says, "8GB Extra Dropbox Space  →  Pay what you want/can; No set price!"

On Freelancer.com, users are getting hustled by job posters who have them jumping through hoops to complete prequalifications for getting hired: pass an online typing test and send them a screenshot of the results, and sign up under them for a Free DropBox account "to receive work files".  None of the applicants are hired.  The same job is then posted and reposted under various dummy accounts, with tens and twenties of hungry applicants getting scammed by it.  For each one that signs up, the referring DropBox user receives 1 GB of additional free space.

Just wanted to let you know what you were enabling with that ad.