BSD benefactors get a good feeling and a word of thanks for their contribution.
The difference in the amounts of money received by both institutions shows how much are people willing to pay for the former vs. the latter.
RedHat's model it's clearly more effective than simple charity, but I don't see a difference between RedHat and any other OSS-reliant contributing vendor. As an example, Juniper funds FreeBSD development based on sales/support of their high-end networking products, and contributed the MIPS port included in FreeBSD 8:
http://www.enterprisenetworkingplanet.com/news/article.php/3...
Blue Coat contributed the new L2/L3 SMP-improved rewrite:
http://www.internetnews.com/dev-news/article.php/3835746
The main difference is that these companies make their money by incorporating FreeBSD into their products, are not required to provide all the source to their products, and thus can contribute back improvements as they see fit.
There's two routes for money to take:
1. People donate money to the FreeBSD Foundation, which then funds FreeBSD development.
2. People pay for RHEL, and then RedHat uses that money to fund Linux development.
Is there really any significant difference between these?