Online Advertising Depression Proof???

I was wondering yesterday, well actually it was more like last week; is there any business that is Depression proof.. not just Recession proof?

Even in the bleakest of economic downturns there will still be sellers looking for buyers and buyers looking for sellers.. albeit cheaper sellers than previously but an "economy" will still exist since people that can afford food and shelter will buy it.

So, the question: Is online advertising the best investment? Since the internet did not exist back in 1929 and if the current global economic woes continue in a downward spiral to oblivion it would be interesting to see the impact to online advertising. Peronally, I don't think we will be able to understand if it is the best way to reach customers until the economy turns upwards and we can do all the statistical research we love to understand the impact of the internet and online advertising in a time of global recession.

I would be greatly interested if anyone knows of any current, as in real-time daily research coming out regarding online advertising budgets and strategies during the current economic downturn.

On a personal note, I still think online advertising is the best option since an advertiser can see results fairly quickly and measure effectiveness at a much lower cost than the more traditional forms of advertising.