Site submission companies

Does anyone have any good experiences with companies whose only purpose is to submit your site to engines and directories?

Personally, I wouldn't bother. Very little traffic comes from 99% of search engines out there that aren't Yahoo, Google, MSN, etc., and typically, if you are linked to from another page that is indexed by a search engine already, then you will be too eventually.

Submitting to directories may be a little different, but again, the main directories you could easily submit to yourself, and I expect most directories those companies are offering to submit to are just terrible.