That was my feeling too knowing nothing about WSGI... I read all 3 of your attempts to explain Paste and I think this one is much better than the ones before but still maybe not basic enough...
Maybe a bit more structure would help as well, it might be just me but some more headlines, a kind of table of contents even for an article as short as this would help. There something like "What is WSGI", "How does a server fit in", etc could fit in.
I guess an example of a specific server + paste + application (that's the way it works, is it not?) like apache + paste + ? would also show more than a lot of explaining.
I read your stuff quite frequently and always wonder how you find the time to actually do stuff and at the same time read/investigate/try in all other web frameworks and other tools... That's actually something you seem to assume from the casual reader. I do read a lot about some of the (it seems) 100s of Python web frameworks but have not been able to try one as there are so many and I am always looking for a really good solution Paste might be to get to.
Just some ideas, actually writing a good documentation and explaining what something is for all kinds of users is very difficult... (something I am experiencing myself at the moment)