Marketing in itself is not social, it never has been and it never will be. Though sometimes there are activities that are a core example of social design and that could be qualified as a marketing. Dropbox is such an example. To give you a bit of background Dropbox is introducing a new photo import and sync option in the new version of their software and to make sure it works they offered a beta.
So far, nothing new. It is just a beta and of course in beta direct user feedback is preferred and there is ongoing conversation on the forum. What might be interesting in this case is that the announcement was made on the forum, not somewhere on their blog or other more formal channel. However this still isn’t really social, it is just a conversation. However the thing that made it more social was just one simple incentive: if you use the product and do an upload of 500MB of pictures you will get 500MB free.
Dropbox is not just requesting for people to spend their time with the new beta of Dropbox, Dropbox is instantly giving back. By doing so it is no longer a traditional beta which is just asking people to spend their time and do your work in finding bugs. It is not a traditional beta in which you can get early access by spamming your friends or in which you can get extra disk space by spamming your friends. Dropbox ensures that the experience is becoming worth sharing and can be beneficial for all, instead of introducing a new Ponzi-scheme. Dropbox makes it social by making sure there is value delivered to the ones participating in the beta, even if they don’t give any feedback. Plus they make the news about the beta worth sharing and your first picture upload to Dropbox is worth sharing, since all of a sudden you have 500MB of disk space for free.
By doing so Dropbox is using the three basics of social design: delivering value for the individual without demanding value back, making it worth sharing and making it conversational by allowing direct feedback from users. And by doing so they create even a bigger return than when they would have done a traditional marketing campaign or traditional beta around their new release.