If you are trying to woo away Dropbox customers, one of the features I use a lot in dropbox are direct links. Sometimes, I want to send a large file to someone. In Dropbox, I right-click, generate link, and send it to the user. I don't know and don't care if they are Dropbox customers, I know it will just work. Right this second I need to send something to someone, it's in my btsync folder. I don't want to share the whole folder with him. I don't want to convince him to install btsync. I just want him to get the file. So for now, I have to use 3rd party services to send it.