What types of directories are seen as sources of paid links?

What types of directories are seen as sources of paid links?

Fábio Ricotta from Brazil asks:

"Will Google consider Yahoo! Directory and BOTW as source of paid links? If no, why is this different from another site that sell links?"

Are Directory Submissions Worth It?

Are Directory Submissions Worth It?

My view on directory submissions. Watch Matt Cutts' video