In a way, that is in alignment with their founding goal of organizing human knowledge. An ad is just a piece of data (eg Bob is selling shovels for $10 + shipp

In a way, that is in alignment with their founding goal of organizing human knowledge. An ad is just a piece of data (eg Bob is selling shovels for $10 + shipping), with the additional metadata that someone really wants you to see it (eg Bob paid Google $100 to tell every person who searched for "shovels" that he's selling shovels for $10 + shipping). Selling ads is organizing human knowledge. Yes, you could argue using a market system is not the best way to do this, but it is a way to do it.