Google takes more than half of the market share of mobile ads, crowding out other media companies such as Facebook and Twitter.
In contrast, Facebook has only 13-percent and Twitter has about 2-percent, according to eMarketer.
However, it should be noted that both Facebook and Twitter's mobile ad numbers were nonexistent in 2011 and have consistently grown in the next two years.
In 2011, Google had 38-percent of the mobile ad market.
Across all digital platforms, Google continues to reign as not only the largest beneficiary of digital ad spending in the US, but worldwide as well, eMarketer estimates.
Google's success is attributed to monetization on YouTube and growing mobile ads. Let's also add that Google has been doing this for a long time -- more than a decade is like a lifetime in the tech field -- so it has a leg up on the competition. It also has the power of a hugely popular search engine and a household name. It's likely the reason that Google has more than a third of all digital ads and its next competitor, Facebook, has only 5 percent.
Google has done well in the ad market, which is likely why its stock price is at $872 at the time this was written. However, it's unlikely that other companies will be able to emulate its success without a strong search engine and another five years in the business.