Nagani - 7:50 pm on Mar 8, 2011 (gmt 0)

Do you mean that only one of them appears on the first page of the SERPs at any given time? If so, is this also true for variations of the targeted keyword or keyphrase?

Yes, only one domain appears at any given time. I checked other keyword variations. It shows the same domain. The other domain is in hibernation for all keywords. But I copy some texts (around 15 words) of inner page and paste in Google, it shows the domain in hibernation only. The reason might be Google didn't index the copied content. There is no noindex,nocache tag in the page. I don't know if .htaccess can block some page not to index. There is no robots.txt in those sites. Obviously they do not seem to be familiar with SEO. All they do is to include the keyword in the title. That is all. That is a money keyword. Travel site.