At first glance, Diigo seems all over the map. The service offers bookmarking, highlighting of text within a page, commenting on a site for others to see, sending options, groups for networking and much more.
Diigo has been made as user friendly as possible by its developers
The advantages to the developer is they don’t have to worry about the very complicated system architecture issues that usually require a brilliant IT engineer to solve. Instead they can focus on writing the code.
It’s dead simple. Amazon’s services still require a lot of very technical IT knowledge to utilize
When they open it to PHP, a ton of PHP developers will flock to it. It will be free, or at least very cheap, and much easier to manage then a shared host or a dedicated server.