If you are doing any serious link building, you have undoubtedly come by sites claiming to sell you a manual directory submission service. I know I have. We research the SEO service space fairly regularly to stay on top of the industry and I see this all the time. I often try these services to see what they offer. So many of our customers ask us about directory submission, I feel that I should know what's what.
In my experience, these SEO firms that say they do directory submission manually mostly are not. There are a couple hints that clearly give away their underlying automated systems. For starters, you are probably going to get a software generated report showing the submissions they did for you. Second, if you start to browse through the submissions, you will see that the text is exactly the same at each directory where you have been submitted. I don't know too many humans that type the exact same thing over and over. Finally, when the price tag is just so darn low, you know there is no way that anyone could afford to do all those directory submissions manually for you. I know they send all this work to India, but even still.
So if you accept the fact that most manual directory submission service offerings are really not manual, the bigger question is "Should you care?" And I think the answer is yes, but not for the obvious reason. Many think that manual is more white hat and somehow protects you from Google. I'm not sure how this association between automation and black hat came to be, but it is fairly nonsensical. After all, Google is perhaps one of the most automated public companies I can think of. They crawl the entire Internet regularly. Their entire advertising system is completely automatic. Yet nobody considers Google black hat. Automation in the car industry was hailed as a great boon to productivity. Microsoft was a hero when they automated typewriters through computer word processing (okay - they were not really the first to do this, but you get the idea). But somehow automation in SEO is bad?
Leaving the automation debate aside for the moment, the reason you should care about manual submission is that humans introduce variation to your text and links. And as we've discussed many times at Hubshout, variation is natural - and natural is good for SEO. So as you consider directory submission as part of your SEO campaign, remember a few things. Google says that submissions to relevant sites in your niche is positive. This includes directories. Google says that natural is best. Manual submissions in directories are bound to look more natural than automated ones.