If that number seems low for the runaway success story of the internet age. Google wants you to believe that it's just a question of market definition. google rejects the idea that it's in the search advertising business, an industry in which it holds more than a 70 percent share of revenue. Instead, the company says that its competition is all advertising, a category broad enough to include newspaper, radio and highway billboards. Google's argument is not simply that it's not a big bufly. If you believe the company, it's not even that big...