How is this done?

With a site like:

http://www.windowsuppliers.co.uk/regional_conservatory_companies.html

Where the information is sort of like that of a telephone book/yellow pages. Would the webmaster of this site have typed in individually all of the listings himself? That would take ages and ages!!

Notting

 

http://www.rigby-research.co.uk such companies may provide you with a database at a price.

 

Cheers Max

 

And, if they have a competitive site around, they could have just gone to the other site's source code.

It only takes a few minutes to get in that site via "view page source" and copy the source code for all those links and addresses.

 

As max pain said, if the information is contained in a database it can easily be bought/sold. Information like that gets sold all the time. Phone number databases, zip code databases, ip-2-country databases, etc. If the information is going to get looked up often, chances are somebody has made a database of it and is selling it somewhere. Think about zip codes. There are hundreds of sites on the net that can tell you what city belongs to a certain zip code, or what the zip code is for a city. Do you think they looked up all that info themselves? No, they just bought a zip code database and implemented it into their site. Takes no time at all if the information has already been gathered for you. If you're the one doing the gathering though, then yes it can take a while. Usually there are teams of people who do this and they get paid for it.