martinibuster - 3:11 am on Sep 19, 2008 (gmt 0)

>>>But what makes one paid link safe and another not<<<

As leadegroot said, you're paying to have them check if your site is worth including but also to make sure it's in the best category, doesn't have a spammy or inappropriate title and description too. Editors are paid money to sort through submissions, they don't do it for free. Why should the review be free? Even DMOZ isn't free, someone is paying to keep that site online.

Believe it or not, I've had one of my sites declined by Best of the Web. Best of the Web has been around in one form or another before Google and DMOZ existed, and since about the same time as Yahoo, 1994. You're not paying for a link, you're paying for a review to be included in a directory. So that in a nutshell is an answer to your question.

There's plenty of room to debate but ultimately the questions you're raising can only be answered by the search engines. Part of the answer is how well can links be determined to be paid or natural and what effect to the SERPs will taking them down have.

Anyone who is performing any sort of SEO is surely attempting to manipulate Google search engine results. So if they frown upon paid links they should frown upon all SEO...

Not quite. There's more to SEO than that, just as there's more to eating than stuffing food in your face. :) A good part of SEO is getting back to fundamentals of creating good site architecture, knowing what things may trigger less optimal results, and understanding how search engines view content and rank it. In other words, it's making the site accessible to the search engines and managing their interpretation of what your pages are about.

My boss is asking whether it's safe to buy these links.

It's wise to consider your risk tolerance and develop a link building strategy that takes that under consideration. A strictly citation-based campaign (i.e. take a look at our site. Like it? Link it. Thanks!) generally is slow going and it's unlikely to result in receipt of your desired anchor text. So understand that if you decide to take that path.