Google is taking a lot of flack lately because it’s launched tons of apps but none has had even a fraction of the success of Google search. BusinessWeek gave Google a big kick in the head, as did Scoble, and many others.

So why hasn’t Google launched anything as successful as the original search? Because it’s a pretty darn tough act to follow. Google search was life changing for everyone on the web, but life-changing applications don’t come along that often.

You can see this when comparing Google’s reach to other popular web apps, like MySpace, YouTube, Digg, and Flickr.

Google Reach Comparison</a>

On any given day, more than 25% of people on the web use Google. (Yes, Alexa is imprecise, but gut check says this is directional correct.)

Even the much heralded (and hyped) MySpace and YouTube have only a fraction of the reach. MySpace does compete with Google on page views, but that’s from a lot a MySpace power users.

Google search is in a class by itself. Is it any wonder that Google has not been able to reproduce this kind of dizzying success?

I wonder if Google is like one of those musicians whose first album is such a runaway success that they are never able to outdo themselves — think Alanis Morissette.

Don Dodge wonder whether Google is a “one trick pony.” Perhaps a more apt phrase is “one hit wonder.”

What’s most sobering about the chart above is how much distance separates Google search from all of the other web apps chasing the same blockerbuster success.

I’ll end with my favorite refrain — the key to Google-like success is making apps that are life-changing for AVERAGE PEOPLE — even for Google.