Google is one of the most profitable companies on the planet for a reason!
That reason is their AdWords advertising program. They make a lot of money from it, because advertisers, small, medium and large businesses keep coming back. Google's PPC revenue from AdWords for 2015 was $67.39B. It's Google's main source of income and they will continue to encourage people to use and to develop the AdWords platform.
Some of the biggest spenders on AdWords spend $40 -$50 million dollars a year on AdWords, and they would need very good ROIs (return on investment) to justify such a large adspend.
There is an enormous amount of traffic available. Over 3B searches a day, 90B per month, 1.1 trillion searches per year.
That's not counting the traffic on YouTube, or on Google's huge display network, which Google suggests covers 90% of the entire internet. Google also has mobile apps and the AdMob platform too. So it is still the largest form of traffic available today. And don't forget 900B users of Gmail, which can also be used to advertise on.
Search traffic is still the most targeted and relevant traffic you can get. With traffic from the Google search engine, users are actively seeking your product or service. This means that in our experience search traffic is some of the best converting traffic available.