Do you think NY Times sells more newspapers because they report about the race?
Not any more than they do when the Times covers the Yankees when they're in the postseason.
But people still see the paper or the website and then they see ING (or TCS starting next year). That's what they're spending all that money on.
Grete Waitz brought a lot to the table. As did Uta Pippig who at the time of competition, was not a US citizen. But those athletes were highly marketable. They could give interviews in clear English and they weren't shy or anxious about it (I saw the Kipsang interview in Berlin ... OMG).
Haile is another example, great charisma, and that's one of the reason he gets high appearance fees. Bekele however, forget about it.
No argument there. They're paid because they're good, but more personality would garner more money.