According to my opinion it is a mixed idea. I mean if you want to promote your site with all of your skills I won't recommend you to use those sites. It looks like as a shouting for search engines come here index me! I think this isn't the natural way to get indexed. But if you have a traditional business and all you want to is to be available on the Internet, I guess you won't worry about SERP and PR so it's supposed to be an ideal way to get into the index.

Completely agree with Bagi, people should not be seduced by this offer of "submit your site to 10,000" search engines, there is not such thing as 10,000 search engines, not even 100 engines worth mentioning online.

You will get better result with carefully choosing links from quality website (NOTE WEBITE with contens and NOT directories) than you will get from the so called 10,000 search engine submission.

Also not that they usually said "submission" which does not necessarily mean the sites will be accepted or listing in a fraction of mostly link farms your sitw will be submitted to.

Thanks for the info guys