The Rise of Google, the Ascent of Facebook and the Decline of Everyone Else

If you pay the slightest bit of attention to Internet advertising, you know this. But it’s always good to see it spelled out: Look how ginormous Google is!

This exclamation point comes courtesy of Zenith Optimedia, via its new (scaled back) ad forecast today. It pegs Google’s share of the overall Web ad market at 44 percent, a number that has been steadily increasing for years, with the exception of a one-year hiccup in 2009.

The other takeaways are also old news: Microsoft, Yahoo and AOL are foundering and have been for years (hence their new alliance). And Facebook is starting to generate a real ad business — as opposed to just a very sticky Web site.

And based on everything we’ve heard this year, the 2011 column will look just like the ones preceding it. Except it might show even steeper gains for both Google and Facebook, given the moves both are making (YouTube and display ads for Google, new tricks like “Sponsored Stories,” plus the overwhelming attractiveness of an 800 million user base for Facebook).

Quite reasonable to assume the two of them will end this month with more than 50 percent of global spending.