It's pretty simple. They made a better wheel. The others weren't really innovating, but Google jumped in and added a bunch of innovative improvements to the way search engines work. PageRank, for example, and a proper page scanning search, instead of just using a bunch of metatags which webmasters were abusing and misusing to get the results they wanted.
So when you used Google, you got the site(s) you were looking for more often than you did with other search engines. It doesn't take long for people to catch on when the improvement is so noticeable, and from there on, word of mouth, help and support people start using the phrase "google it" and it took over.
So when you used Google, you got the site(s) you were looking for more often than you did with other search engines. It doesn't take long for people to catch on when the improvement is so noticeable, and from there on, word of mouth, help and support people start using the phrase "google it" and it took over.