Let me explain. Let's say my keyword I want to optimize is "green giraffes". But the domain greengiraffes.com (singular, plural, no hyphen, hyphen, etc.) is not available. I know that the search results for "green giraffes" and "about green giraffes" are essentially the same because "about" is a "stop word". Does that therefore also mean that the domain name "aboutgreengiraffes.com" is as good as "greengiraffes.com" in terms of SEO value? Are all stop words equal in that regard, or a shorter one (such as "e" or "z") is better?