For the past few months I have been collecting Bid information from Overture/Yahoo! Search Marketing’s View Bid tool for 200+ keywords.

Data collected includes: Top 10 bids on Y!/Overture, trended over time with information on which company bid on the term, ranking of that bid, and creative/copy.

The above graph trends average bids on Yahoo for Home Loan related keywords, which probably is the most highly contested (and expensive) category in the SEM world – with bids as high as $25.

Notice that in recent months Home Loans related bids have been trending down. My resulting deductions/hypothesis —

• Google’s (and Yahoo’s) search revenue per click is decreasing. Search marketing revenue constitutes a majority (95%+) of total revenues for Google, and Home Loan related keywords bring in much of that.
• Lower bids = is there less competition? Is the Online Home Loans market cooling down a little?
• Marketers are becoming smarter about SEM and are better understanding search ROI and market dynamics. Bid prices as a result might be settling into more rational ranges.
• Maybe it’s just seasonality? — a summer slowdown. You’ll notice in the graph above that September is trending up marginally for Purchase and Refinance.