I know that they work out special pricing with certain distributors in exchange
for helping them to get their product promoted. Ubuntu released Parallels in its
repositories. It was a trial version that expired after I think 15 days with a
special offer to Ubuntu users afterwards and Linspire offers similar discounts
in its CNR library for Linspire members. Codeweavers who make Crossover Office
and Wine often offer discounts for people who buy through a third party just so
that they can get maximum exposure.