Google's Similar Pages Feature

How are the listings chosen?

[nzmatt]

Anyone know what this actually is, how it works and what SEO significance it has, if any?

[ThomasB]

I think it works via linking structure.

If page B and C get both links from sites D, E, F and G they're both somehow related and the topic could be similar.

[nzmatt]

Hi ThomasB - yes I think you are right.

Intuitively, the results are hardly "similar"; but I guess that's up to the particular webmaster and the links they gather.

This means it is far better for SEO to have authorative, on topic and high PR sites/pages appearing as 'similar pages'...

[nzmatt]

What happens if B & C then link together - is this good or bad for Google B & C's SEO?