DataComm,
You’re making this too complicated for yourself and your clients …and chasing a low return on anyone’s investment.
It’s not illegal to use a street address as a domain name, but why?
The house will be sold soon enough, and then what? You’re left with a useless, “seo’d” url. Then what?
If you put the street number and name on a craigslist ad, google picks it up nearly immediately and makes it “seo friendly” without messing around with unique url identifiers. An MLS listing does the same thing. Otherwise, who is really going to search for a particular address without first knowing the property is for sale. And if they know the property is for sale, and have the address, then what difference does it make to have a url by the same name and address?
If you’re dealing with a unique and expensive property that will take months to market (or an apartment complex, or commercial building) then maybe it makes sense to seo the domain name. However, I just don’t see the necessity or advantage otherwise.
If your clients are not trying to unload turds, and offer a genuinely good deal, which your customers should be sifting out and concentrating on… then the domain name will be of little, short term help.
Meantime, the url you want to seo, should reflect the name of your client’s company (and/or what they do). This is where their repeat business is going to stem from. I’m talking about seo-based branding, etc.
Maybe I’m missing the point, but with a one-off transaction, craigslist and the MLS produce all the seo-based traffic necessary.
I hope I don’t sound like I’m raining on your parade. I just say use the domain for building up traffic for several properties, not just one, and let craigslist, MLS, etc, etc. produce the seo-based traffic to the specific property.