I have a site that I've sold a dozen text ads on or so. Yeah, most of them asked for a yearly link. It really depends on the popularity of your blog and how much they're willing to pay. I get an average of $300/year from the text link ads I sell, but I think your site could be more popular than mine so you probably want to ask for more.
Btw, you have a great web site, Mike! Nice work.
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