The Value of a Quality Link
There are only so many hours in a day, and SEO folk have to decide where to spend their linking energy. On one hand, they could scour directories and get links accepted fairly regularly. That is what directories are all about after all. On the other hand, they could dig deep into the internet and try to find blogs and sites that are related to their topic, and send out emails to those sites asking for a link exchange. Success comes far less frequency using this method.
At a cursory glance it might seem obvious that directory efforts would be yield far better results…but the results I’ve witnessed suggest otherwise.
A link from a directory may or may not be seen by Google, and it may or may not be added into their database of links pointing to your site. It all depends on how much respect Google gives that directory. Normal blogs and websites, on the other hand, are rarely shunned by Google, even if they only have a pagerank of one or two.
An extra added bonus to blog links is that your link may appear as a separate incoming link for every page of that blog. This means if the blog places your link on their homepage, Google may have 15-20 of their articles indexed with your link in it, giving you 15-20 incoming links. You may have spent a lot of total time getting that link up there, but if this situation occurs, it is definitely worth it.
Ideally, you could utilize both directory and personal linking – directory for the short term, personal for the long term. But if you HAD to choose one, I would vote for personal linking every time.