This is a different website with some interesting entries. Some of the German stadiums are much bigger than I had imagined. http://www.worldstadiums.com/ It includes all sports and also includes future stadiums, which surprisingly contains Ashton Gate as a 27,000 all seater
Different countries have different systems. In Germany I think many of the clubs have a significant fans element involved in the running of their clubs and this respect I think you will find more clubs in Germany average over 40000 than in the Premier League. Whereas in the NFL it is the league which is the business. Both of these systems I think are more sustainable than the Premier League. Perhaps in Germany greater fan involvement has led to bigger stadia.
I notice Bristol Speedway stadium is shown as a 100000 plus venue. Is there something the Gas have not been telling us?
I suspect that the reason for the higher number of clubs in Germany that average over 40,000 is because their league system is concentrated only on the two top tiers. Below that football is regional and part time, as indeed it is throughout Europe. The English league system with five full time professional leagues of 116 clubs has greater depth of quality players but does spread the support away from the top tier. The Championship is the fourth best attended league anywhere in the world (correct?) and some clubs gates in League One are rarely, if ever, seen in the third tiers of other countries. Another factor is simply that Germany is a bigger country by area and each large city, generally only has one club in the top tier. Hence Dortmund will pull 80,000 whereas greater Birmingham for example has Villa, Birmingham City, WBA, Walsall. Plus Wolves and Kidderminster and Coventry not too far away.
German gates are similar at four levels. the English system hardly had greater quality either as coaching and youth development is superior in Germany hence the number of German playing throughout Germany in top divisions. In the top divisions due to fan involvement gates are increasing and the demographic is far younger / more diverse. the attendance demographic in England is 40+. that is unhealthy for the future of the game as a spectator sport. Using Dortmund as an example and their gates of 80,000 should mean in the region of 160,000 should be watching Villa and the Blue regularly. The stats do not match up. Borussia Dortmund are an interesting model of how an FC can be run, unfortunately the vernein model will not be sighted in England.
I always remember someone at work said "nothing is forever" when citing Rank Xerox and photocopying machines and the same applies to football. The age demographic for English Football supporters is a ticking time bomb. The next generation will not tolerate what we have to put up with now. Technology has to come, as does greater fan involvement and respect fro the referee. Many footballers have the intelligence of an amoeba, get paid ridiculous money and behave like spoiled children. Perception is everything