Chuck, vBulletin is by far the most widely used forums software and there are thousands of modifications available for it that plug right in and work within the vbulletin code base. VBgallery is one of those scripts. It plugs in to vbulletin's product system.
I'm merely suggesting that you guys do something along the lines of what you did with Photopost - you created a couple spin-off scripts in Classifieds and Reviewpost that use the same code base as Photopost. If you did the same thing with a classifieds script that is basically spin-off of VBgallery I know a ton of people would want it. I see so many people asking about this in the vbulletin.org forums all the time. Vbulletin owners are spoiled with how easy it is to plug in add-on scripts, and they'll be more inclined to use a product if it plugs in easily and uses the vb template system.
Yes, Photopost Classifieds can tie into vb using its headers and footers. But it doesn't "plug in" to it the way VBgallery does. That's what makes VBgallery so great! You can go into the vb template system and add in vb variables and do all sorts of mods. I'd love to see a classifieds system that ties in that well.
There is a classifieds product on the market now that plugs in to vb, it's called VBclassifieds(.com). It's too bad you guys don't try something like that.