It is true, search was not a business. Back then, most startups depended on DoubleClick banner ads for revenue generation (just as today most startups depend on Adsense). DoubleClick was not a viable business model and Google considered that to be their very last option.

Google was running thin on cash until they finally adopted Bill Gross' GoTo.com advertising model (aka Overture) in 2000. So for the first 2 years, Google was a cash cow with no business model around its search either.