When I see these pop up, I sometimes wonder if people click, read and evaluate the blog before posting "Added, now ad me"

If you simply want the link exchange experience of a blogroll, I guess that works but...

If you run a "twink blog" and someone offers a link trade with "Grandpa gets a diaper change blog", how does this help your traffic?

Also,

Do you check the links on the offered link exchange to see who else they link to?