Ok, So please correct me if I am wrong! I am no guru and still in the early stages of learning! Am I right in saying that search engines look at sub-domains as indipendant site? ie if I had the main site at www.mysite.com and a domain.mysite.com than search engines would treat it as 2 seperate site? So with this in mind. would I have anything to worry about if rather then keep registering new domains, i just set-up lots and lots of subdomains? For example if a sub-domain got penalised by a search engine, would it potnetially effect all the other sub-domains? or if a sub-domain got banned from adsense would it ban the whole site?
I've read all sorts of stuff regarding subdomains. Some people say that a really spammy subdomain can affect your main domain, other says that it won't. Personally, I go crazy with subdomains and have LOTS of them - I haven't noticed any problems. I've registered several 4/5 letter pronounceable "nonsense" domains purely to run subdomains off. However, I'm not running AdSense on any of them, so I'm not sure what Google's policy is on that.
Well mostly people use subdomains if the main domain has got PR 3-4 so that they get the benefit too. Actually subdomains should be used if its a part related to the main domain but should not be used extensively. U can also checkout the Google's Webmaster guidelines.
Well what I am thinking about is to create a mu installation purely running it on one neiche using sub-domains. Initially I will stay away from adsense I think until I can see the effects in rankings. I have a PR3 on the main domains (hoping to go PR5 on the next update due to some good link building).
Matt Cutts said "Google will roll out in a few weeks a new filter to make sure only two results of a domain (no matter subdomain or folder) will show up for a search". http://www.seroundtable.com/archives/015621.html
That was very interesting to know, however it seems that the update is designed towards sites that dominate the search results. So are longs as each sub-domian it targeting different keywords, then it should have little effect on what I am trying to do, as my aim is not to try and domainate search results for single sets of keywords.
Doesn't this only affect people who setup multiple subdomains to target the same keywords/phrases as their main domain? So if you're using your subdomains for different niches (that would never show up in the same search results anyway), then it won't really matter. ?? EDIT : iamsgf beat me to it
Google no longer considers subdomains to be treated as separate domains due to the widespread rampant abuse of many so-called "SEO professionals" misusing them to manipulate their index. And this is a perfect example of that. In your case the subdomains would be treated as regular directories as far as Google is concerned. That PageRank will be diluted to the subdomains as well. However, from an information architecture point of view, if your subdomains are going to be related to the main site while still being distinct (such as sports.yahoo.com weather.com and mail.yahoo.com for example) then I don't think you'll have much of a problem with the search engines. Depends on how it's used. The example I gave above is a perfect example of when to use a subdomain. (A forum is another good one - especially if you need to do a subdomain site search - sitepoint.com is guilty of this - try looking up an article and chances are you'll be flooded with forum posts, more than a few of which I've written.) That's what I normally do as well - see above.