I have been asked a few times on the performance of PageBlaster - by John Mitchell from Snapsis. Having advocated and used it extensively for some time, and in the commercial builds we deploy, we seriously wouldn't run a highly trafficked site without it. I've heard nothing but rave reviews about it from everyone who has taken the time to learn about it's functionality.
But how do you know if a site is running PageBlaster? It's hard to know whether a site is running any modules that are not displayed on pages in the normal fashion, so you can't view the source of a site and detect it, but here's a great example and how you can identify if a site is running PageBlaster.
Earlier this year, the AFL.com.au website was launched - it's one of the biggest DNN sites if not THE biggest site using DNN. I remember the discussions regarding the performance with the DNN build with the site and the implementation of PageBlaster made an extraordinary difference. John Mitchell who has an extensive understanding of DNN, DNN code, DNN performance, has, I believe a very good handle on what makes a DNN site run well.
So here's a little tip for you to establish if a dnn site is running Snapsis - PageBlaster.. and what version - which as of writing today - was 2.4.
This handy URL is http://www.web-sniffer.net - although if you've got fiddler installed, I believe it's possible to detect as well.

So if you're looking at ways to increase the performance of your websites, then it's definitely worth visiting and buying this great module. It's one of the must have modules for every DNN website.
I should be paid to talk about this - but I'm not - it's such a great product and it will make a marked improvement on your slow running dotnetnuke website.
Nina Meiers