In the case of Google ... that purpose is to serve ads.
It's like saying that human's purpose is to consume food.
Food is our way to get energy we need to do something - anything, actually. We would die without food, but are we limited to that? (Okay, some people actually are, but these are few).
Google did A LOT - probably more than any other company - to organize and structure data, make it more accessible - THAT is their purpose (and I believe Brin or Page actually told that).
Google's mission statement is: "Google’s mission is to organize the world's information and make it universally accessible and useful."
Nothing in that statement necessarily presumes the use of ads to pay for it. If users said "we'd rather pay 1c per search than see ads" (and the math added up) Google would change to that instead.
I'm currently an intern at Google. Everyone knows where the money comes from, but day-to-day, engineers talk about what's best for the users, not about what's going to help connect ads. That's what the ads division is for, and that's only one of 7 product groups.
Everyone else is trying to make products to help people, and even ads feels like its helping too by finding you the products you want more quickly.
Exxon Mobil Corporation is committed to being the world's premier petroleum and petrochemical company. To that end, we must continuously achieve superior financial and operating results while adhering to the highest standards of business conduct.
There are generally three kinds of mission statement.
The plain mission statement which comes out and tells you what the company does, as if you'd never heard of them before. This is best typified by the Five Guys fast food chain's mission statement: "We are in the business of selling burgers." However, most companies will at least throw an adjective in there. I honestly like Blizzard's: "Dedicated to creating the most epic entertainment experiences... ever."
Then there's the framing mission statement, like Google's, which tries to put a context around the plain work they do. Another example is Starbucks, who claims a mission to "inspire and nurture the human spirit – one person, one cup and one neighborhood at a time." These are the ones that try to be aspirational.
Finally, there are the ones that seem to have been written by lawyers or legislators. These drone on endlessly are so awful they demean the dignity of the companies that have them, so I won't finger anyone to protect the guilty. However, you know for sure you're reading one about the time you halfway through and find the word "stakeholder."
It's like saying that human's purpose is to consume food.
Food is our way to get energy we need to do something - anything, actually. We would die without food, but are we limited to that? (Okay, some people actually are, but these are few).
Google did A LOT - probably more than any other company - to organize and structure data, make it more accessible - THAT is their purpose (and I believe Brin or Page actually told that).