I have never seen the point in using a service for SEO. A little time spent studying so that you can include keywords and so on and your website will speak for itself.

And really you should be able to make your site speak for itself-nothing else will sell it like a wealth of fresh and useful information. And fresh really is the key-whether you choose article submission or posting them on your own site, you need to keep the stuff coming. If you write a bunch of articles at once, don't post them all at once. Stagger them, one every couple of days for as long as they last.

Links should be meaningful, not just the thousand in an hour directories. And for that to happen, you need good content-it all comes back to content! People will re-visit you if you have good, fresh content.

I could go on all day about this, it's my pet subject.....