Can you post a link to your site?
Sounds like you might be encountering the old "hammer looking for a nail problem". If your prospects "love" the idea but aren`t signing up then you`re taking their feedback the wrong way. They`re saying "we love this but not enough to pay for it just yet".
Find out why. Might be a marketing problem, communication problem, or lack of market demand.
I usually get around the early adopter problem by giving it to someone for a little while.
Find a potential customer you trust, and that is tolerant of the growing pains, and give them the service as part of your "Beta Test". At the very least you`ll get great feedback. Make sure they unsedstand that it`s only for 6 months, or whatever time period you feel is enough to get about 10 more people on it.
When you`re thiking long term, is the loss of revenues of one person for 6 months worth not getting other people signed up?
Sounds kind of like a niche Froogle.
I built a site along those same lines back in the late 90s pitching used cars in El Paso, Texas. It was hard getting dealers onboard at first until I gave it to them for free for the 1st 6 months and promised to do all the uploading, inputting etc myself.
After those first 180 days were up I had no problems whatsoever collecting revenue from them for continued service. They had a chance to see how the site would benefit them and gave me a chance to build traffic to the site.