Warren
This site is here so we can all help each other and there is no problem with anybody promoting anyones products or services (even your book!). The point is that there is a limit - no-one wants to read the same post time and time again!
As far as sponsorship goes, somebody has to pay the costs of running this site but that does not allow them to post anything, anywhere! There are many of suppliers of equipment that have posted, and can continue to post, relevent information on products they supply, it just has to be in moderation.
As has been mentioned before, those that put the effort into the site will get the most out of it!
Regards
Forum Admin
p.s. there is now an agreement new members will have to read when registering which also recommends they use their real name, or company name. This is a professional forum and people will take posts more seriously if they appear to come from a professional. If there's anyone who has since thought better of the user name they've chosen they can change it in the profile section.
I trust that clears things up for you wazzastud.