Hi Chris, Robert here, Eli Overbey answered that question with a preference for the subdomain in his article at: http://elioverbey.net/subdomain-vs-new-domain-better-seo/ because:
- subdomains may inherit and pass ranking metrics
- subdomains give an impression of an consistent brand
- concentrating all your links on one domain
Please note that Eli’s answer might note be right for you. Let’s place this in the context of your question. You are starting 2 brand new enterprises. Therefore the transfer of existing ranking metrics from domain to subdomain is not that all that relevant. And you have to consider how much more prominent your real estate domain would be over the vacations rental subdomain to make it worthwhile.
Further note what Eli stated, URL length is an issue. In your case. it is reasonable to presume that both of your subdomain and domain will be quite long. So keep in mind the anecdotal testing on URL length that John Doherty did back in 2011: http://www.johnfdoherty.com/lessons-from-google-about-url-lengths/
You might also suffer from stuffing too many keywords in an URL if your sub-pages or blog posts happen to become, let’s say vacationrentals.pumpkinrealestate.com/10-unkown-scenic-locales-in-pumpkin. Search Engine Journal cites Google in their article at http://www.searchenginejournal.com/url-structure-seo/11801/
“Best SEO URL practice: it is recommended to have no more than 3-5 words in the file path (note: this is not really about the whole URL but the actual file path after the last / in the URL but should be mentioned anyway as it indirectly demonstrates Google’s overall treatment of the URL length).”
And Matt Cutts is cited to state: “Google algorithms typically will just weight those words less and just not give you as much credit.”
Therefore it is wise to consider also whether you will be having a lot of sub-pages or blog posts under your vacation rentals subdomain. Because while the sub-domain main page may pass the mustard, for Google, it is reasonable to expect that pages under it may not.
As far as branding is concerned, I like to think of the brand in terms of the social signals you are sending to the public and to the seach engine(s).
Therefore think of it thus: would you like to have a single social media channel for both of these properties? Let’s say for tweeting out the latest news items. Or organising a Facebook page that people can like to get the latest offer. If yes, then reasonably, having a single brand is important to you. If no, and these two properties require seperate channels then these two properties really are seperate brands (as brands these days are all about being social, right? - we face them through social media more and more). And therefore, that tends to suggest that seperate domains may be the way forward for you.
Finally, when it comes to concentrating links — consider how rare people linking to your site will actually be (you might be part of a legitimate real estate association that promotes each others offers) or you plan to do viral or mini-viral postings. It also might be that your vacation rentals subdomain might be getting more links than your main domain for more people may be interested in short-term vacation rentals in an attractive lucrative place where owning property is cost prohibitive for most.
Chris and everyone, this is my first post on Moz Q&A so if you like the answer — make sure to like/upvote it.
PS! Take a look at the screenshot attached. I did a search for “Maui Vacation Rentals” on Google.com in English from a continental US IP (Boston). As you can see, there are only 3 organic results beyond the fold. It is very visually striking how paid advertising from Google AdWords and Google Maps dominate over even those 3. And add to that the factor that 2 of 3 of these organic results are from TripAdvisor and HomeAway who, one might reasonably presume, might be prominent on your SERP pages for your exact domain match as well. So perhaps focusing on Google Maps / Google Places whatever you decide should be a key thing to do?
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