Also adwords (the product that is actually sold). Brilliant idea: users only see ads relevant to their interests; advertisers get qualified users, and instant feedback and adjustment; google gets the highest price possible (by advertisers bidding against each other).

Google is double the good guy: (1) helps users for free, because advertisers pay for it (like free-to-air TV); (2) advertisers can't complain about google's high prices, because it's the other guy who bid it up (like selling munitions in an arms race).

I believe google came up with this independently BUT goto/overture did it first, patented it, sued, and google settled.

So far as revenue is concerned, this is Google's only product.