In her annual state of the Internet industry presentation at the Web 2.0 conference today, Mary Meeker outlined, among other things the structural issues in the online ad and tech growth, and how densely connected they are to the larger economic activity. Imagine delivering that to the nattering nabobs of Silicon Valley…oh wait, they got the Sequoia memo before that.

As Saul outlines her presentation, ad revenues grow and shrink three times as fast as GDP over time, and if that is unchanged next year, which is Morgan Stanley’s current forecast, ad spending for all media will fall by 4 percent. And if it gets slower than that, say a 2 percent drop in GDP, that would bring a 10 percent reduction in ad spending. That’s for general advertising, and there isn’t enough historical data for online advertising. BUT, during 2000-2002, online advertising fell by 27 percent. This time, she says, the online trendlines would be closer to general advertising.

Among all this gloom, one hope: mobile. You can download the presentation here.

Advertising Spending & GDP Growth (click to enlarge):