What does this mean on first step up setting up a campaign? "Having two "twin" domains that both resolve forces them to battle for SERP positions, making your SEO efforts less effective. We suggest redirecting one, then entering the other here."

[cschwartzel]

I am BRAND new to this, and setting up my first campaign. I choose subdomain, and entered www.pdsaz.com. This is the message I receive:

We have detected that the domain www.pdsaz.com and the domain pdsaz.com both respond to web requests and do not redirect. Having two "twin" domains that both resolve forces them to battle for SERP positions, making your SEO efforts less effective. We suggest redirecting one, then entering the other here.

[ZephSnapp]

OK, so basically you need your site to only appear in the Internet Universe once, otherwise Search Engines will be confused and think you have a clone.  Since cloning (duplicate content) is frowned in the SEO world, this will force the Search Engine to consider them seperately and decide which one is correct.

Fixing this is relatively simple.  It means creating a 301 for one of your two options.  Here is an article that explains how to accomplish this: http://www.dailyblogtips.com/how-to-setup-a-301-redirect/

If you have other questions please let me know, I'll be glad to help!