Give your site a custom URL. Each site comes with a link of http://agentname.phpatl.com. If you already own a domain, you can "forward" your domain to your link above. In this case, your domain would simply forward the user to the PHP Realtor site link. This should be a simple free option to use.
Both the option above and full Domain Mapping have full SEO records. If you are just forwarding your domain, search engines and the URL in your navigation bar will be http://agentname.phpatl.com and the about page would be located at http://agentname.phpatl.com/about.
If you want to take the branding of your website to the next level, Market ATL can perform a domain mapping integration with your custom URL for a one-time fee of $25. This will allow on all pages on your site to have the link of http://domainname.com/ and or http://domainname.com/about.
*Domain Forwarding with Masking is also an option to retain your domain name in the address bar but, when this happens, all pages on your site will have the same URL in the address bar. You will not be able to distinguish between one page or another from the navigation bar. Also, for SEO purposes, only your homepage will be indexable by search engines.