The secret is nice sites like
http://www.bodybuilding.com and
http://www.elitefitness.com
"If you are an overweight adult webmaster who wants help loosing weight" you might help but if they don't have no motivation they will get nothing.
If like 90% of the webmasters are overweight not a lot of them will have the motivation to go at the gym or do more sports.
Half of the people who starts at the gym give up before 3 months (that is normal people who likes sports)
And Overweight webmasters (who are never doing sports) will be much much worst like 9 out of 10 webmasters won't have the motivation and will give up before they hit 3 months at the gym.