—Yahoo developed 29 new products over past four years—but there was little growth in the number of new products per year over that span: It had six new products in 2005, 10 in ‘06, six in ‘07, and seven in ‘08. (This covers developing a major new product or expanding an existing one into new markets or countries.)

—Product-development expenses increased at an average of 35 percent per year during the same period.

—Some of the expense increases may be from acquisitions made over the years, which likely would have led to an increase in headcount. But clearly revenue from those deals didn’t remotely keep pace with new expenses. Product-development expenses as a percentage of revenue increased from 11 percent in 2005 to 17 percent in 2008.