You have your listing on 123 Main Street on the web, now how do you get people there? You could email them a link, which is not always convenient..or you can simply tell someone to go to MainStreet.HomeIs4Sale.com.
A semi custom domain allows you to have a simple internet address where you can direct your clients. Allow your clients more time to look at a property rather than looking for a property.
Personal Domain URL: http://123-main-street.properties.listerassister.com