Which is why it is so costly, dropbox did not build the infrastructure. I was about to go with a paid plan from dropbox, but once I checked the price of Google Storage, dropbox seemed ridiculously expensive. Dropbox charges $10/month for 50 GB. Google charges $20/year for 80 GB (starts at $5 for 20 GB, goes all the way upto 16 TB). Seemed a no brainer to me. I use InSync (https://www.insynchq.com/) which gives the same sharing capabilities. I ended up getting 1 TB storage from Google.