The WPMU blogs are not a secret. Tierney's new tool will be much like Pete's tools - not much use if not used properly. If you haven't made 100s of blogs with the Pete's tools that Kurt has provided for free, then this method will not be very appealing.

I don't consider any of my blog building or promotion methods very secretive. I simply build till I get bored and then build more. Over the last few months I have automated it similar to the extent of the tool that Tierney plans to release in a few weeks.

The problem with mass promoted tools is that the fingerprint they use to find the WPMU blogs will be the same for every user. New blogs appear every day and I do spend a lot of time building and filtering my blog list.

You still need unique related content for these blogs and some way to manage it all. Blogs are not an end all solution. They need to be promoted. They drop out the the SERPS and are often removed by the hosting webmaster.

On the plus side: they work great with RSS feeds, interlink easily and every post is a page with an unique URL to promote. They gain PR rapidly. Lots of PR3 and PR4 pages after a few months and 1000s of PR1 and PR2 pages.

The biggest benefit over Blogger blogs or a self-hosted blog network is the varying IP addresses.

It is just another tool to get words on a page and some backlinks.