Jerimiah Yap

Santa Clara, CA

According to market research firm eMarketer, search giant Google will have a 15.4 percent market share of total online ad revenue in the United States by the end of the year. This market share will be enough for Google to top Facebook.

This year alone Google will earn an estimated profit of $2.31 billion in the United States. Last year the company earned $1.67 million. Google's revenue has steadily increased since 2010. Four years ago Google owned just 12.1 percent of total digital display ad revenues.

EMarketer estimates that Google will have 18 percent of digital display ad revenue next year and it will increase by 3.2 percent in 2014.

Social media website Facebook will have a forecasted 14.4 percent of ad revenue by the end of the year. EMarketer also expects that rate to grow in the next three years -- although not as much as Google's.

Yahoo! came in third with 9.3 percent. Yahoo! used to be the leader of ad revenue but dwindling number of visitors has the website scrambling for audiences. EMarketer is estimating that Yahoo! will decrease in market share in the following two years.

EMarketer reports: "The overall forecast for display has been slightly reduced from the previous forecast to reflect the mix of lower prices for display advertising on ad networks combined with the reluctance of some major brands to make extra-large investments in digital display advertising."

The big reasons why Google will top the list is its advertising program, audience on YouTube and mobile ads.