Thanks for the quick response.
I don't think I have explained myself very well!
I didn't mean content – as I stated we already have our own content and are not in the least bit interested in, as you put it, “ripping” other content. Also we build our sites for users not search engines and consequently in this instance are wholly unreliant on SE traffic.
I meant the processes of registering, managing, renewing, pointing and creating microsites for thousands of domains and putting (our) content as well as advertising onto them.
All the research we have done suggests that creating such a system would entail a considerable investment on our part and that is something that we are well prepared to do.
We have also been unable to find any off the shelf systems which come close to doing this. However it seemed reasonable to ask whether there were existing systems which forum members were aware of (I imagine some will be managing a considerable number of domains?) before commissioning such a project.
The question was a bit of a long shot and your response further affirms that this is something we will most likely be commissioning ourselves.
Thanks again for a timely response.