How Yahoo Blew It . The way Google and Yahoo charge advertisers for their marketing campaigns is very different and explains the fate of the 2 companies.
I have had an Google Adwords account for a long time, and and you are billed only when someone actually clicks on their ads. I don’t bid much, since average revenue per visitor is very low, but I spend some money monthly.
Yahoo has recently started offering India specific PPC advertising, they charge your credit card first . Then they disapprove all your ads because you do not provide contact information. I have an informational website, I do not sell any product or service, why should I provide my contact details? Then they don’t bother to reply to your emails. Yahoo certainly will not get any repeat business from me.