Hey Julie,
Thanks for writing in and sorry for the confusion. Our link index is not created using our crawl test or campaign crawls of a site. The index is actually a completely separate database compiled by crawling the web and following the links we find there. Your site will only be included in Open Site Explorer if we find links to your site from outside sources.
Just so you know, here's how we compile our index:
- We grab the most recent index.
- We take the top 10 billion URLs with the highest MozRank (with a fixed limit on some of the larger domains).
- We start crawling from the top down until we've crawled 90,000,000,000 pages (which is about 35% the amount in Google's index).
Therefore, if the site is not linked to by one of these seed URLs (or one of the URLs linked to by them in the next update) then it won't show up in our index. Most new sites and links will be indexed by our spiders and available in Mozscape and Open Site Explorer within 60 days, but some take even longer for many of reasons, including the crawl-ability of sites, the amount of inbound links to them, and the depth of pages in subdirectories.
As Pixelbypixel mentioned, Majestic SEO and Ahrefs often have a larger index than we do because their tools are exclusively focused on links, while we have a wide variety of tools with an overview of a site rather than on one specific aspect of SEO or marketing.
I hope this helps! Please let me know if I can help you with anything else.
Chiaryn
Help Team Ninja