If you use similar tags to a high profile blogger, it can help with faster indexing and rankings, at least from what I have observed.

In many ways the effect is similar to linkfarms, using the tagging as a central hub. Many commentators complain when they see Technorati tag pages appearing in the Google SERPs, because Technorati doesn’t have a huge amount of editorial control over the content of those pages, they are more like search results.

In that situation however for any specific query, you are unlikely to have more than one or possibly 2 results appear.

Subdomains

In theory Google are meant to have changed the way subdomains appear in the SERPs, limiting how many subdomains can occur from a single TLD.

Matt Cutts addressed this in more detail

As mentioned on Search Engine Round Table, there would likely be exceptions to the rule for things like the large blog hosts, and Matt pointed out IBM as a likely search that should give more results.

So it would be perfectly natural for WordPress.com to be one of the exceptions, because multiple unique blogs might talk about the same topic, and give a good user experience, which is what Google strive for.

Tags As Subdomains

I notice on a query I used to receive occasional traffic from but for some stupid reason people are competing for it now – it rarely brought more than one query a day when I was ranking first, though it was targeted.

WordPress training in Google (note:- US geolocation non personalized)

The initial results are great.

One of the results is the tag page on WordPress for training – that is covered in my previous article which was questioning whether this is allowed – it is a tactic I would be keen to use if it was officially sanctioned, as would many blog networks.
Actually at least one blog network does do it.

Currently I use internal tagging and I know many of those get discounted as being poor quality, whilst others that are used more frequently are actually better results than any individual permalink page.

However further down the long-tail things get extremely messy.

When you study the pages, you discover that these subdomains were in some way intended for localized tags, so if your blog is in Polish, it would appear on a Polish tag page. Unfortunately the content on the pages is identical.

The English tag page for Training Resource could be looked on as a useful page, though it is still user generated content and easily abused, and a small webmaster doing the same might be looked on as a linkfarm.

The problem is that the Brazillian Portuguese subdomain contains identical content.

If that happens across for example 200+ different languages, then it represents a problem, especially seeing as WordPress.com is a commercial interest.

Whilst I think the original tag pages have merit, I am going to take a harder line with these subdomains.

If they had gone to the trouble of using a translation plugin to make the pages useful for discovery, they would have been useful, even though the translation wouldn’t be perfect. The title and headline being translated would make a significant difference on English search results, even if the URL remained the same.

But Automattic didn’t translate the pages, and they didn’t restrict these subdomains to only blogs written on that specific language.

As they might both read this, Matt & Matt, this in my personal opinion is search engine spam.

These are worse than your typical scraper site.