In my opinion what you are doing is unethical (possibly bait and switch and illegal) and if you were a REALTOR, I'd already have you in front of the board. Go to the main search page and type in 23606... It's an old area of Newport News where lots aren't often available and when they are they are very expensive.
You feature your non-existent homes in 23606 (I think you feature them everywhere, because it's similar no matter what zipcode). This makes 13 of 15 listings on the first page of the search your fake listings. If someone calls you up to get a new house in 23606 for $356,900 (http://www.trulia.com/property/3020683771--Simon-Elite-2700-A-Better-Way-To-Build-Newport-News-VA-23606), you can't possibly deliver anything close to that because the cheapest lot is $189,900. So let's subtract that lot price from your ad price and we're left with $167,000... Are you telling me you can build a brick front 2,700 sqft. home for $61.86 a sqft.?
No, you can't, so how is that not misleading? Oh wait, because you have this line if they click further in the description, "Also, most advertising includes estimated lot price, but this home price may not include land cost as it may be a build on your lot custom home program. Lots are not always available in all subdivisions for these open listings"... your tacticts are deplorable and I really don't understand how Trulia doesn't see this as decreasing the validity of the site. (it has to mess with their valuation algorithm as well)
Want to not spam or mislead Brian? Run banner ads and side ads for new construction, build on your lot... and use realistic prices. Don't adveritse like you have ready made houses for sale.