Don't go anywhere near the topic of selling it, in any way, shape or form. Google staff searches Google's database for all references to "PR," "Page Rank," and "PageRank."
only write about it, if you are 100% sure of what,how,when PR operates, and if that is the case then you should be a very wealthy man :)
There are things which you just should not do, your post highlights 1 of them.
If you do discuss PageRank [google.com]™, be sure to give Google a link, it helps with their PageRank™ and it's a nice gesture when you include the TM, in fact, I think it's mandatory. ;)
Now I'm so glad that what I've written about Page Rank is entitled "Pizza Rank - Hold the Pepperoni." It's forthcoming, and I'll be certain to include a link to Google.
Search for "pagerank" on google and you'll see many pages discussing pagerank, most of they based on the published parts of the algorithm.
They don't seem to be penalised.
If they were penalised they wouldnt be in the SERPs tho... ;)
How many more have been written and have been penalised?
So what are they doing, hand reviewing?
We have published several articles on this topic, and we have definitely not been penalized. It wouldn't make much sense for Google to go into this kind of sensorship.
At the end of the day, the same rules apply to this subject area as do for writing content on any subject.
As long as the information is unique, accurate and references sources, then it is valuable content and nothing can be critised about it.
Like perkoch said, it would be a bad PR (public relations) move for Google to sensor this kind of content.
Beachboy said it - you can talk about it but don't offer to sell it as a "commodity" - or your sausages will be chopped for Christmas.
Right, NutsAndBolts, that is what I said. Thank you. Hey! 800 posts! :)