Versatility
Now, I'm not saying you can play David Villa at left back or anything crazy like that but, as far as strikers are concerned, David Villa is a versatile one. He can play with another strike partner in a 4-4-2 formation, as he did alongside Fernando Torres at the World Cup in 2010 following the opening defeat to Switzerland, he can play in a 4-3-3, as he is currently doing for Spain alongside Torres and David Silva and, perhaps most importantly for Spurs, he can play as a lone frontman in a 4-2-3-1 (or in a 4-5-1 as he did for Spain at the 2012 European Championships). Given that Andre Villas-Boas favours a 4-3-3, Villa would fit in to his ideal formation. He would also be able to play in the 4-2-3-1 that Villas-Boas was forced to employ last season, before really having the chance to mould the squad in to the one he really wants. Essentially, the point I'm making here is that Villa would definitely fit beautifully in to the Spurs team.