I immediately thought you were a scammer.
<rant>
You know what pisses me off the most about a site like this? Where is your contact info? Demo? Screenshots? Samples? Names? Email? About? Who the hell are you? You provide no names, no contact info, just an overly minimal site that links to another even less informative site with no names. And I see this so often that it infuriates me. It breaks the basic most fundamental rule of the web which is, Trust and Authenticity. AKA Credibility.
http://who.is/whois/freshplum.com Even your WHO.IS info for your domain is anonymous. The only idea I have that you're not a scammer is that your HN account nick007 is 1000+ days old. And your first name might be nick and you might be a part of Ycombinator's summer 2011 class. Your clients aren't going to play the clicking game like I just did to try to find out if you're a scammer or not.
https://twitter.com/freshplum: Here's your twitter, again no names.
http://www.quora.com/Freshplum: And your Quora, again no names. Just "a pricing company".
I know I'm comming off as an asshole critic (the kind HN needs less of) but, WTF man. I had to dig your names out from the bottom of your press release. The one document on all your sites that actually tells me something.
Who is spreading this philosophy of 1 page anonymous sites that ask you for credentials?
Here's a one page website I made. http://www.timeforzen.com. All it does is stream free creative commons songs. I'm not even selling anything and I still have an about page and contact info.
</rant>
(Also for those of you who are saying 5% is too high, don't forget ebay and amazon fees add up to 11%-20%. Amazon is so expensive that I can't afford to sell my calendars on its site. And Gumroad allows you to sell links to digital content by charging 5% as well. So it's normal.)