Dan because when I visit their homepage, it looks like something real. I can visit their site, I can sign up, I can start listing my names.
With peace and love, DomainNameBroker looks like somebody started putting it together one afternoon, then got bored so they tossed up a stock photo and an email address and called it a day. It barely even looks like it exists, it's a little too soon to be promoting it. I wouldn't trust them to design landers that convert, since they've put zero thought into conversion optimization on their own homepage.
I just don't see how they're in the same category. I'm not saying DomainNameBroker isn't a good service or isn't doing fantastic things for their clients, I have no idea, because they don't offer any indication that they even exist.