"Obviously, everyone is focusing on CPC...Profitability is way down for five quarters now, for Google, quarter after quarter. Paid clicks, the rate of growth is slowing," Jackson said. "We're facing a scenario, where I think in a couple of years, we might hit peak search."
The rise of mobile will lead consumers to want to search in new ways, which may open the door for others to enter the search space. The number one contender may just be Apple — one of Google's fiercest competitors, he said.
"I think that there is a big opportunity right now for someone to step forward and assert themselves for a new way of getting people information for doing search in a mobile world," Jackson said.
"I don't think typing in a blue box is the ideal format for a mobile world. And I think the best opportunity out there to displace Google in this area is probably Apple's iri."
However, Google could still turn things around, and the company is doing some things to make up for the decline in CPC.
Google shopping, for example, has been changed to only show paid results in a way that should generate a lot of money for the company, Jackson said. This too, however, could pose a new problem for the search giant.
"The question is, is that move going to degrade the service, is that sort of the tip of the iceberg?" he said. "And are we going to start to see paid search results in other areas of Google and is that going to degrade the experience?"