Utilize your financial knowledge, give your answer or opinion to the input question or subject . Answer format is not limited.

If a company has already IPO'ed and sold its shares, what is the incentive to keep making money? 
Because people bought their shares under the premise that they would make more money and if the company completely lied about that they will be subject to several civil and criminal violations. If people didn't believe the company was going to make more money, they would have valued their shares lower during the IPO by not forming much of a market at all.