[greglindahl]

Note that they're building a graph of the web for SEO purposes, not a search engine index.

[b4hand]

Our index and API are primarily used by web marketers. We have no interest in building a general search engine, but there's nothing special about it that is for SEO.

For the most part, we just provide general facts about the web, and we've been contacted by academics on more than one occasion for data sets.

[greglindahl]

Is that kind of data called an "index" by any community, though? Seems quite confusing to me, and you can see some of the other folks commenting here that it's confusing.

[b4hand]

We do have a traditional inverted index over anchor text. That's just one aspect of our data set though.

Originally, that was a larger focus and that's the name we've always called it. I could see how that might be confusing.

However, I do think the common name for the data that we collect is called a backlink index, at least in our industry.

[greglindahl]

Ah, that's pretty neat that you have an inverted index in there. I'm about to build one for the Wayback machine.