Dropbox started sending out emails to its users with a special offer granting 48 GB of storage free for two years. That feels like a killer approach to convert non-paying users to subscriber status because when you have all those gigs available online you will be tempted to keep them there. If conversion does not reach their target levels they still have the options of: (a) extending the free period, (b) lowering the entry level subscription, (c) offering a special discount for a period of time to new subscribers.
