Thanks for the compliments. I believe that the "popular" rating was removed because it presented a "positive feedback loop" - check out this link: http://en.wikipedia.org/wiki/Positive_feedback
The main problem with having a "popular" rating that also factors into the ordering/ranking of results in a list is that if a listing becomes popular for whatever reason, it will be moved to the top of the list and will thus get more organic page views by people who go to the JRD and click on the listings at the top. This will continue indefinitely, so all you really need to do is get a ton of people to view your listing one day and then you are set for a while. Heck, with that method, you could even pay for google ads directly to your listing for a day and then just sit back and relax.
I do agree with your desire to order the listings by level of forum participation. I believe that we should have a few factors that are used to calculate the ordering/ranking:
1. Level of Joomla Forum Participation - number of forum posts, forum Karma, etc
2. Level of Joomla experience - number of Joomla sites built, maybe a score on some kind of Joomla knowledge assessment relative to the category of the listing, maybe a score on some kind of general assessment test of relative knowledge?
3. Number of comments on listing (good or bad)
4. Reviews/Ratings of Listing (like JED)
With that said, "1" above would be easy to calculate in theory, but if you add in different forum accounts for each member of a company and other factors, it could get murky, plus you might see people giving negative karma to competitors. "2" would be very valuable, but you would need a team willing and qualified to create such tests for each category. "3" is very valuable and easy to calculate, but in theory you could have a listing with a ton of negative comments at the top. Then, only "4" makes sense and is easiest to accomplish. You could even factor in the rating and the number of comments, which it seems is how the JED does it. Furthermore, "4" would easily incorporate "2" by extension just because if people get better reviews it is likely because they know their stuff. Finally, "4" would also incorporate "1" if you motivate people to give you a good rating in the JRD in your forum signature. Help more people, get more positive reviews, get to the top of the JRD.
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