In the tradition of the hotel industry it is trying to displace, Airbnb is now offering a “stay two nights, get one free” deal worldwide. New users who book before January 17 for travel before March 31 get up to $300 credited toward one or two or more nights. Airbnb is also offering the deal as a carrot for its Verified ID program, so participating users will have to supply a scan of their driver’s license or passport. That system has been somewhat slow to roll out — and it’s hard to imagine people will get more excited about sharing their offline ID with Airbnb in light of ongoing news about data breaches from established retailers like Target. Maybe $300 will help.