Totally baffled on server/capture/http

[jeffs at speakeasy.net (jeffs)]

If anyone has managed to get the server/capture/http auxiliary module up 
and running could they explain how to set it up to me?

Running with the defaults makes the victim's http process scroll through 
a list of sites defined in the %content% placeholder in the index.html 
file of the process, to finally come to rest on what appears to be an 
arbitrary site and waiting for user input.

I also see that an autopwn process could be set and am I to assume this 
would be setup on a different metasploit window?

I attempted a mitm arp poisoning scenario with ettercap and same results

The info description simply states that it is a fake http service to 
capture authentication credentials.

I don't understand the logic of this module and would like to.

Thanks.