Here's a summary of a great piece in BussinessWeek today with a grand-finale in the block quote below.

Why will online weather the recession better than other mediums? Well...

1. Online has come of age as a medium.
2. It is accountable and engaging.
3. It's an iron law of marketing that word of mouth is the most powerful medium that money can't buy.
4. Marketers are spending digital dollars to create "earned" rather than "paid" ad placements.
5. Online has the capacity to reach consumers with precision at specific points in the buying process.

In short, Madison Avenue won't come out of this ad recession the way it came in. Why would advertisers budget on faith when they could invest in measurable returns? Why would brands lavish dollars on mass media when they could target only those consumers who matter most? Why would marketers continue to allocate less than 10% of their budgets to interactive (in measured media), when consumers are spending more than 35% of their time with interactive platforms even today?