If you are not a friend then you are a spammer!
As it was describe in the article this search engine algorithm could ensure 100% spam free content. The way Twingly plans to achieve that is by starting the search for blogs from a “legit” known blogs, traversing down and expending the list using links to other blogs posted on these sources. The assumption is that a link from a reliable source will lead to more reliable links.
I think that this is a great idea in general. I’m not sure how big and rich the result is going to be and what will happen with new blogs that are not so well connected.
Maybe starting with a wider list and using social networks to cross reference with a blog owner will lead to a bigger scoop. Most likely a blogger won’t have a spammer friend in his network. If he has then this entire network could be labeled as “dirty”.
As I wrote in here you’ll find the blogger in multiple places with many different friends that can lead to a nice reliable source of other bloggers (not explicitly linked from his blogs). This requires to be able to match blog with a friend profile.
One more source of “clean” links is the trusted blogger’s Twitter twitts. I see lots of linked tossed around by bloggers that I follow. As you all know we need to read (be fed) before we can write (feed). It is possible that just peeling links that appear in Twitter streams we’ll end up with a search engine providing access to numerous handily picked and filtered link list. It is sure scalable.
So, keep your network “clean” and don’t speak (make friends) with spammers!