Google really does not have a monopoly. Advertisers do have a choice. Microsoft has more of a monopoly on technology/internet/media than Google does.
Webmasters would favor Yahoo! soft. They'd have an extremely high traffic network probably equallying out to Google's users and traffic. Being that said a publisher network would pay more than Google since they both already individually do.
I think it will happen later than sooner .. but it be good to have a merger. that wil only bring improvements, wont it ?? hmm
i think so to beat google they should do something uniqe togather. but to buy next one is not a good salution. Uniqe thing boost them but this thing would not work