There are so many different ways to put this together other than what is in the picture but how ever you do it, I strongly suggest your get some Sugru mouldable gule or some crazy glue when you are putting this up as it doesn't snap and stay.  
The cats love it, we have it outside and they are on it all the time, they really like the scratching polls and there is always one or two cats on it all the time.  

Pros: Affordable cat tree
Cons: needs to be glued or attached with some type of gule....