Just an outside point of view so I'm not sure if this is at standards, but how are people being made aware of your website? It looks more like a tool, so how are people coming across it?
The main thing is you want clients to come to your site, so why/how are they finding out about this site? This is more of a communication issue, connecting the sites capability to the right audience, knowing how to get the right people to the right place. Perhaps the site is fully functional with the use of a database and php coding, but you're missing massive elements when it comes to communicating to regular people, and without sounding rude, the design makes me feel a bit uneasy. Could be why it's not being utilized, because I don't see something like this being searched for right off the bat. Generalized comparisons are not easy to set up off the bat, it would be better to grow your site into a platform that does product/brand listings/comparisons. But starting off just like that, you basically need a user who is looking to do product search. You really need a reputation or some anchoring elements for this to work in my opinion.
Though, if you leading people from an already existing platform, and then to this site, but no one is using it, then it would be purely a design issue. Because the site doesn't really make any sense to me the way it's designed. Essentially it's just a barebones tool and the driving element is a user who knows exactly what they want when utilizing it.
I'd suggest re-assessing what you are aiming for with the website, and communicating with a designer and marketing group to chisel it out properly. But.... where are you getting the massive amount of data to back up the challenge you are setting for yourself by creating a tool(website) like this?
Can you explain what this website offers to the user, and what your overall objective is? Because, it's so general, it seems like you are aiming to show product listings from.. what? All online sources? Which sources? I'd say it's definitely not realized properly unless it's attached to the primary ecommerce website, to which there is no presence on this site.