I think that Airbnb is a good alternative to to a hotel, especially outside of popular tourist destinations where there are fewer options now. A lot of the discussion for Airbnb seems to be focused on what its doing with cities that already have a high volume of rent by the night accommodations. Look outside of those areas, though, and I think there is a lot more potential for Airbnb to fill a need.
For example, I have an Airbnb listing in Lawrence, KS that it averaging just over a 50% occupancy rate. Right now, we have a family with 3 young children staying it in for a few days. They are planning a move and needed somewhere to stay while house hunting and visiting schools. We're renting them a bedroom, bathroom, living room, and office (with air mattress set up for the kids). They also have access to a back yard and kitchen. They would have had trouble in our city finding accommodations for their family that were nearly as comfortable, since we don't have timeshares or many suite-style lodgings in this area.