Use of subdomains, subdirectories or both?

[HaCos]

Hello, i would like your advice on a dilemma i am facing. I am working a new project that is going to release soon,  thats a network of users with personal profiles seperated in categories for example lets say the categories are colors. So let say i am a member and i belong in red color categorie and i got a page where i update my personal information/cv/resume as well as a personal blog thats on that page. So the main site is giving the option to user to search for members by the criteria of color. My first idea is that all users should own a subdomain (and this is how its developed so far) thats easy to use and since the domain name is really small (just 3 letters) i believe subdomain worth since personal site will be easy to remember. My dilemma is should all users own a subdomain, a subdirectory or both and if both witch one should be the canonical?

Since it said that search engines treat subdomains as different stand-alone sites, whats best for the main site? to show multiple search results with profiles in subdomains or subdirectories?

What if i use both? meaning in search results i use search directory url for each profile while same time each profile owns a subdomains as well? and if so which one should be the canonical?

Thanks in advance,

C

[RobertFisher]

C

This is one of the reasons I love this forum: it requires thinking because many who ask questions are thinking. (think about it;) While I understand what eyepaq is saying in one sense that search engines "could" treat them as stand alone; it appears search engines do/could because as the subdomain holder you are not seeing links going only to the main domain or other subs, you are the one who controls it, can move its hosting, etc.  But, according to Google, they do not in the sense of linking:

If you own a site that’s on a subdomain (such as googlewebmastercentral.blogspot.com) or in a subfolder (www.google.com/support/webmasters/) and don’t own the root domain, you’ll still only see links from URLs starting with that subdomain or subfolder in your internal links, and all others will be categorized as external links. We’ve made a few backend changes so that these numbers should be even more accurate for you.

Note that, if you own a root domain like example.com or www.example.com, your number of external links may appear to go down with this change; this is because, as described above, some of the URLs we were previously classifying as external links will have moved into the internal links report. Your total number of links (internal + external) should not be affected by this change.

So, as for external linking, it is clear that if there ever was a question about domains and subdomains, there is none now. But, that does not mean you should not use subdomains. Eyepaqs point around user abuse is an excellent one, but you should also be monitoring this like a hawk.

At the end of the day, I would think that using subdirectories is going to be easier if you are planning on a large site. But, the ease you mention for the user with the short domain name is intriguing. I agree with Muhammad on sub domains might get a little expensive and, if your choice is to use both (I wouldn't as it seems to me that you are creating more and more work for your dev team) the canonical should be the subdomain.

Again, thanks for the thought provoking question.

Robert

[eyepaq]

Hi,

Since it said that search engines treat subdomains as different stand-alone sites,

** Search engines could treat subdomains as different stand alone sites.  Usually they don't. A good example when they do that is the blogspot subdomains - and that is because those are in fact separate stand alone sites.

In your case however, since it's about users, similar with blogspot somehow - google can treat them at som point as separate websites.

whats best for the main site? to show multiple search results with profiles in subdomains or subdirectories?

** My personal opinion is that from a user point of view you should go with the subdomains as you do right now - it make sense, it's easy for them to use those urls, to link to them and so on.

You could lose some link equity for the main domain if some or all subdomain will be at some point treated as separate domains but if you put everything on a scale, it will balance as advantages on the subdomain approach anyway.

What if i use both? meaning in search results i use search directory url for each profile while same time each profile owns a subdomains as well? and if so which one should be the canonical?

** To be honest I do see the point / advantages in doing that.

One other advantage is that if you go with subdomains and google will count them as separate websites, if one of your user is ding something stupid (trying to rank with it and start building gambling and porn links to that sub domain you will be safe with the root domain and the other users won't be affected.

Hope it helps.

Edited to underline the word could 

[razasaeed]

Hi HaCos,

Well it depends on how many users are there? thousands of users with thousands of sub domains is an expensive option. Go for user subdirectories instead of sub domains. And as each user got a sub domain too, so make that sub domain canonical of user sub directory. Hope this answers your question.