Companys pay you more money to review their product or advertise depending on the amount of rss subscribers you have. Would a company like microsoft want to pay a blog with 10 readers $1,000 to write a review on vista, or pay a blog with 100,000 readers $1,000 to write a review on vista? Obviously the one with the most subscribers. Then their product will get a bigger audiance and more people reading about it.
The 24 ways to increase your RSS subscribers is at the link below...
http://www.kedoa.com...ss-subscribers/
This is extremley helpful to loads of people who have blogs and websites. Let me know if i can add anything to the list, and if my post is good.