Where do you usually put them? I see a lot of websites requiring them, and I'd hate to have 10-20 links on one page just to get submitted. Also a little off topic... do those sites that "drive traffic" to your site through links on your site really generate traffic?
Good sites maintain separate page(s) for links to be included. If those links are higher than yours and they contain relevant content to yours, those will obviously drive traffic- how much it depends on the other optimization strategies you do