There are many reasons - but essentially these can be broken down into two parts.
For people who want things built
Because you have better things to do with your time
Because the frustration caused between you and significant others (while you assemble your item) is more expensive to repair with a psychologist than to hire someone else to do it for you.
Because explaining the same thing to 10 x handymen via email and phone calls is too hard
Because there are people out there who actually love doing these jobs - and you, as a loving member of the human race love helping these people out too.
For people who want to build things
Because you're sick of looking for work across multiple sites and contacts
Because you like a place where everything is clearly defined as a record of what you were going to build
Because you love removing that look of frustration and confusion from your customers faces
Because you'd rather have a basic interface to manage all of your tasks and contacts
So really give it a go! What have you go to lose? Then if you find something that is frustrating you or something that you would like to see added - email us! We actually listen - if we get enough feedback from people we will change things and add things to the site.
We are looking at creating the best possible environment within the Assembly landscape - and that can't happen without you!