What I wonder about Dropbox is how profitable it actually is. Assuming five million users and each only uses half their available space, so 1GB. We assume the

What I wonder about Dropbox is how profitable it actually is. Assuming five million users and each only uses half their available space, so 1GB. We assume they're at the top plan on Amazon S3 and people are transfering maybe 100-200mb a month. All in all about 7c/user/month for storage and bandwidth. If we take similar numbers from Evernote (maybe a stretch?) and say 2% of their users subscribe at the lowest price plan ($99/year or $8.25/month), that's about 17c/month/user revenue. So over five million, we have about $500k/month in gross profit. Of course, we're ignoring the cost of providing the upgraded plans. Not bad though, especially if their free/subscriber ratio is higher.