Open Site Explorer- where's that data coming from? Do they scrape in real time or just no?

Hey guys,

It late here so this may be a really dumb ass question but where do places like OpenSiteExplorer get their data from to show you everything from backlinks, to authority?

Also is it possible to obtain the same informaiton as far as the backlinks go by using a search query in Google like link:httw.google.com

Not saying their service sucks but If it can be done for free then I might as well just build a tool for it myself.

They get their data from Google API. The DA and PA that they provide are basically the results of their (OSE) algorithm.

They crawl all of the sites using their own web spider and update the data about once a month.

Here is more info:
http://www.seomoz.org/help/open-site-explorer-faq

Thanks guys for the help. Now I understand how time consuming it must be to collect that data. I'm going to sign up for their services but I wanted to be sure there wasn't an easier way to get my own links.

I have access to opensiteexplorer.org, if you want, I can send you a sample of the report using your desired URL. In this way, you can have a better view of their service before signing up with them.

By the way, they do provide a 30 days trial before you pay for their service.