Microsoft uses google

Yes! How?
Microsoft advertises Windows Live Messenger in Google AdWords! Paradoxically, right?
One pays a competitor to unwind their new product, clearly competing with similar to this same competitor. Another gets money from a competitor for advertising this very product.
I do not know about you, but this situation seemed interesting to me. Firstly, the very possibility of such an intersection of interests, secondly by the fact that this turned out to be acceptable for both companies (who in MS, interestingly, made the decision on rotation in AdWords?).