Many people here are wise enough to know not to pay Domain Registry of America. They're not your domain registrar and are just trying to trick you into thinking they are by asking people to pay a renewal fee. It's legal and they get away with it because they word their notices carefully enough that they do not actually claim to be your registrar, but instead use indirect terminology which leads some people to believe they are.
I just came across a new one which is similar. This time I received it via e-mail instead of snail mail like Domain Registry of America. The best part about this one is they wanted me to renew a domain with them that was already renewed through 2013 with the real registrar.
This one even says "SE Services provides submission services and search engine ranking organization for domain owners. This offer for submission services is not required to renew your domain registration." But when you look at the big red letters at the top and the fact that they plaster the domain name all over the notice, it's clear they're hoping people become confused.
From: Notice of Registration Expiration <email@example.com>
Subject: FWD: Attn: Registration Notice
This is a screenshot of what the e-mail looks like with my customer's information removed from it to protect their privacy: