The Google search page appears on a computer screen in Washington on Aug. 30, 2010.
The Google search page appears on a computer screen in Washington on Aug. 30, 2010. - 
Listen To The Story

By last account, Google had about 65 percent of market share for the search engine market. That's just on browsers in the United States. In other markets in other countries, the number can be as high as 90 percent.

But there are other options. Microsoft has been trying for a while now to get Bing at least in the same ballpark as Google, and while Bing is now the second most popular search engine, it's a long way between #1 and #2. In the days before Google, Yahoo was doing quite well for itself, but it's far from being a legitimate contender today.

It's a little strange considering that only in search does Google have that kind of dominance. Plenty of people use Gmail, but plenty use Yahoo mail and other options too. People like Google Maps but people use Mapquest as well. Google search is towering over its competitors. Today, senators will be wondering if its stepping on competitors in the process.

Dr. Eric K. Clemons is a professor of operations and information management at The Wharton School of the University of Pennsylvania. He recalls running an experiment with students where they were asked to retrieve information using both Yahoo and Google. This was material that wouldn't come up in a search right away, it required digging. "And then I had a colleague grade their exercises without knowing which search engine each student had used," says Clemons. "Then I had some students tabulate the results without their knowing what I was expecting to find. They couldn't find a performance difference between Yahoo and Google."

But while the information returned may be similar, the Google experience tends to be more personalized. Eli Pariser is the author of "The Filter Bubble: What the Internet Is Hiding from You." He says, "Originally, Google was based on this page-rank algorithm that looked at the web and tried to figure out which pages were linking to which and use those as votes for which pages were most authoritative on any given source. But over the last 10 years, Google has realized that that's only part of the equation and the other big piece is what people are actually clicking on when they search for a given topic. And by getting a better understanding of exactly who's looking for what, Google can serve up individualized personalized results. But what that means is basically Google has 10 years worth of learning from this incredibly enormous pile of data that they've collected on who's clicking on what and that advantage just grows and grows every day."

Of course Google isn't just search. It's Gmail, YouTube, Google Maps, tons of others. They don't all dominate their categories like search does. But Pariser says they all serve their purpose.

"Basically, all of those services support each other so that it becomes increasingly easy to use Google search. There are all of these roads that lead to the core product, which is search. And Google understands that it doesn't take much friction in order to change behavior, if it's just one little click or one little step out of the way, a lot of people will go with the default. And in any of these services, the default is Google."

Follow John Moe at @johnmoe