Yes, in fact web advertising has proved to be deep enough to support all of Google! Of course there is a limit to the total amount of advertising dollars avail

Yes, in fact web advertising has proved to be deep enough to support all of Google! Of course there is a limit to the total amount of advertising dollars available and many half-good companies may not be good enough to support themselves with advertising, but there is no question that a good company can do very well on advertising alone.