Just goes to show how important controlling that initial source of reach at a low cost (maximizing efficiency) is for a travel site (remember: TripAdvisor *is* Expedia. It's the Same company - as is Hotels.com, Hotwire and Classic Custom Vacations). This also mirrors the purchase of TripAdvisor by Expedia several years ago - for just about the same reason I'd imagine (buy it now to avoid having to pay to use it as an increasingly expensive advertising/reach source down the road). And - not to downplay the number in absolute terms; I'm sure the developer is tickled and should be - but $3m is peanuts compared to the global ad budgets of the brands above.