If you build it, they will come.
If they don't come, tear it down and build it again. After all, it don't cost nothin'.
I wonder where we would be today if Randy Petersen had taken the attitude that there might not be enough traffic for the InsideFlyer online forum, so lets not bother setting it up?
The internet as a whole is US-centric. We must live with this. Why is the generic Ebay.com the site for the US market, while one needs to specify Ebay.co.uk to get to the UK site?
FlyerTalk also suffers in that many non-US posters tend to congregate in their regional forums (British Airways, Air Canada, Qantas, Airlines of India, etc...) rather than use generic forums that are more appropriate for the subject matter? For example, are threads about security at UK airports more suitable to the British Airways forum than to the Travel Security forum? The non-US posters have themselves to blame if the wider userbase have diminished awareness and consequently cannot identify with what may be viewed as relevant. Some forums on FlyerTalk run the danger of becoming ghettos of regional discussion at the expense of broadening awareness of the often widely relevant regional discussion among the larger community.
FlyerTalk IS a global community, but like any community the onus is on the minority to set the agenda for integration into the mainstream rather than on the majority to open the doors and welcome them with open arms.