There are two types of ways to submit to directories: automatic and manual.
Pros Automatic submission software allows you to quickly post your web site or blog to thousands and thousands of web sites that permit you to link to them, adding your site to theirs.
There are quite a few software applications available for you to utilize that can submit your web site and blogs to different directories with varying types of core information.
There are a number of 3rd party service providers that will spend their time and take your money to submit your sites for you, so that you need not waste the time and energy doing it yourself.
In addition to software and laborers, there are websites where you can input all of the pertinent information for your site and click SUBMIT.
Then, you'll be treated to your web site being listed on thousands of sites quickly and effortlessly.
Manual submissions agencies can easily fudge the records by claiming that they have submitted your site to well over 300 directories, search engines, and news groups and store the list for you in a nice little spreadsheet where you can peruse all of their hard efforts.
In the end, though, the proof is far from reality.
Cons Automatic software and sites do not take into account the different features of search engines and directories while submitting to them.
Search engines and directories don't like automatic submissions.
They consider it a form of spam.
They will do a manual review eventually and once they find any automatically submitted sites, they will block them.
Automatic software will submit to thousands and thousands of directories, but they work off gigantic lists which may have (and often do have) sites that no longer exist.
So your 1,500 sites will probably dwindle down to a real 500.
Categories on directory sites vary greatly.
Software to auto submit your website is limited to what they choose.
Manually submitting your site means you can control where it goes.
Targeted submissions are better than mass submissions.
You want to hit the people who want to hit you Manually submitting to directories allows you to enter better suited keywords and descriptions.
You can't control where your site goes.
There are thousands of sites you've never heard of.
It's a waste of time and money (if buying software or using a service) placing your site where it does not belong.
It's counter productive to your marketing blitz.
In the end it's your decision.
However, remember that manually submitting your web sites and blogs allows you to take full control of where they are placed.
Do your research in order to submit your site effectively.
It's an ongoing project and you must keep up on it so you don't fall in rankings on the sites.
Blindly linking only serves one real purpose: wasting time.