It makes perfect sense to put Facebook type ads on my website. Just like AdSense is contextual to the content, Facebook ads will be tailored to the user. Assuming they're logged into Facebook, like such as with FB comments. Showing ads relevant to their location, "likes", etc. If the money is competitive with other ad networks I could see this being very successful for Facebook.
As a web user however, I would find it as annoying as the ads on Facebook itself.