europeforvisitors - 2:18 pm on Mar 3, 2005 (gmt 0)

I agree with loanuniverse, especially if you're talking about niches where inventory for a given keyword or keyphrase may be in short supply.

Also, contextual advertising (or Internet advertising in general) still represents only a tiny percentage of total advertising expenditures. That means there's tremendous room for growth even if total ad expenditures remain static.