The website for adobe, though I know is obviously supposed to be be famous.
But why is it soooo famous, that it ranks to no. 6? I mean okay people use it and stuff, but it's just like for one time, you download something and that is it! Why is it above some famous social networking sites as well. It only had products for downloads right?

You wouldn't keep downloading products 24/7, but may still be on facebook for a considerate amount of time

What global work rank?

Flash is used on many websites.. maybe that's why? If you don't have flash most sites give backlink to adobe to download it.
Just my guess.. ^^

yupp but not only flash , they have all types of readers and even the great photoshop is from them they have a whole range of editing softwares as well

Yes it has the photoshop suite, flash and so much other stuff to download from, and backlinks are going to be more than any other wbsite, but isn't the ranking more valued according to how many people people visit the site and for how long?

cm00x, the global "world" rank not work rank
It's the rank given to a website according to popularity, backlinks etc.