First, thanks Robben to help Chelsea earn some money. (36M-22M=14M).
Second, sell Robben is a correct decision, we can't let a player which plan to go somewhere to continue play or stay; this can impact to whole team.
Third, Robben is only good perform during first seanson he join Chelsea, then he become a good diver/actor (like C. Ronaldo).
Fouth, now Chelsea have Malouda, Joe Cole, Kalou, Shaun Wright Phillips can play in winger position; without Robben, other players can have more chance to play and prform.