Elements of marketing value for athlete endorsements

As a marketer and cross country skier, I should be able to offer a reasonably objective view on this.  At the highest level, there are four key elements:
1. Target audience reach of the sport (local/regional/global) relative to the brand's audience
2. Brand fit of the athlete (and sport)
3. Profile of the athlete (quantitative/qualitative factors)
4. The intangibles that make a good partnership better than the sum of its parts.
The really successful brand partnerships deliver on all four criteria relative to specific budget parameters.  The first of these effectively drives the dollar value (e.g. David Beckham, probably the world's most recognizable athlete globally vs. Bjorn Daehlie, the most successful cross country skier of all time and little known outside his home country of Norway).  Different absolute value, but both can deliver success.
As a reference point, look at this map of most popular sports by country.  Football (Soccer) dominates, Cricket is top in India and Australia, Rugby in New Zealand.  Football (Soccer) even beats skiing in Norway.  Happy to note that skiing is the most popular sport in Estonia!