When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Subscribing to a forum means having e-mails sent to you when new threads/posts are made... Kinda like you can buy a magazine in a store, but you can also subscribe. Meaning it comes straight to you, every time a new issue comes out... Sort of like that...
You don't really need it, unless you want your mail box filled with e-mails every time some one posts...