Now I like this idea. There is one problem though [excluding other problems that my fellow members have identified] - How long does it take a good person to be a bad person? 1 second! He could get the certification, Sales could increase and then suddenly on his new found publicity he could go bad.
Although I like the idea very much. Instead of just a static "Certificate" we could introduce something dynamic that periodically checks. Like a set of rules or standards defined to Sellers operating with certain protocols. Adding more dynamic rules and introducing changes as and when necessary. [You know this just sounds like one of Cisco's exams!

]
Also distance factor must be taken into consideration. A seller in China may not be able to send his product to New Zealand [after all costs are an important factor] we should have designated members in certain regions to do this. Also a general warning for buyers MUST be attached with the certification so that buyers are aware when the certification was given and when it expires. That would at least bring the level of problems to a lower height.
Yes there will be cheaters, but there have always been cheaters. This could be a good way for some poor Sellers whose business is affected because of them. No battle is won without a fight. We need backups in place to ensure a streamlined process.
A best bet is that "Put your trumpets out!". The best we can do is promote MpxPlayer. I put a post on my blog regarding the Memory hack sometime after Christmas and its a huge hits taker. [10 hits per day for a single post is large for me!] It has some links to the good posts on this forum. Most of the Google search terms have been "MP4 Hack" "MP4 Less Memory" etc. Even if one of them clicks the link, I have a satisfaction of at least making one person wiser. If such a movement was widespread we could be gaining ground. [Giving one post on your blog a primetime slot for a day won't take anything away from you will it?]
Also opinions should be taken from buyers of the certified seller to ensure that his products still conform to the Standards. Any report and he is blacklisted. This could make very big inroads in these scammers territories. That's frankly my opinion.
[Sorry for the warish look, but being a Strategy fan all of my short computer life... it just happens!

]