I think of DW as one of those furnished apartments you once booked for a week's holiday. Not really furnished or decorated the way you would like it, you don't know the neighbours, haven't got half your usual tools or utensils... nice enough as long as you can get out and about but it would need an awful lot doing to it if you were ever to think of living there and, on the whole, you would still prefer not to!

FB, on the other hand, is the car-park assembly point if you need to evacuate a building - you can make sure everyone is still OK but are unlikely to hold long meaningful conversations there!