I stumbled this site http://www.roiworlddressup.com/ and noticed some of the tags at the bottom, but they appear dodgy and as subdomains to that site. The site seems to be aimed at young kids. The links on the left are all clone sites with the same idea. That site has over 30,000 pages indexed by Google. Now you might say oh well Google will ignore them. Not true take a look at one tag/subdomain I found and searched for it (ive no idea what it is): spam 3rd link down.
It reminds me of that other site that managed to get 1000s of pages indexed really fast. I think Google is prone to this technique, but I dont know how he or she creates so many subdomains.
It kind of sucks that people put this kind of stuff up. I understand they want to make money, but it makes the internet experience miserable for the rest of us.
i think its not spammy one.. its one of the best seo trick... The site have good contents and well designing also.... Its my opinion only....
It might be an SEO trick when you have relevancy to what the document contains some of those subdomains are to tap into other bizarre traffic pipelines. For example say you have a domain about shoes yet have a subdomain "sexy-nude women-wearing-shoes.shoesite.com" then times that by another 1000 different pointless subdomains and you will get tons of traffic. lesbains.roiworlddressup.c0m young-girl-pics.roiworlddressup.c0m/ Some of the subdomains are hilarious if you look (bottom of page) Is this done manually though?
they took some most popular or attractive keywords for some domain.. Some time they did by url rewriting tech....