It is a yearly fee. We are currently contacting the existing vendors to see if they want to stay in the program or not, and we're still setting up the payment details for ourselves so this is not going to happen tomorrow. But it will be 1 year, counting from the moment you sign up.
We've argued about the amount of the fee, and settled on 100$.
That is not dirt cheap, but otoh if you are offering a service, 100$ over the course of a year is not a huge deal. I don't know what for example razor honing costs these days, but if it's still 20$, that's honing 5 razors over a year to get it back.
By allowing the sigline to contain your offer for member services (and the other benefits) in return for the 100$, people will see your service every time you post in the forum. And for active posters with a couple thousand posts, that is quite a lot. In the old system your member service was in the classifieds so people had to go look for it, and then it depended on where your service was displayed in the list etc. This system rewards the people who contribute to the discussion.