Braintrust seems to be more company and enterprise centric which is a great market to grow in. Dropbox doesn't have the social component, group feed, and conversation around the media. Soon enough we will allow people to upload any media type and share it with the group and perhaps partner with a dropbox or dropio around hosting and serving the files.

However we are going to stay focused on the socialization aspect of groups and try to address this notion of simple, private, and/or temporary. Definitely more to come!