When I logged onto Facebook this morning I had two invites to join groups outraged at supposed claims the world’s leading social network was set to start charging a monthly subscription fee.As it was so obviously not true I didn’t bother to join the collective rant. Tempting as it was, neither did I join the conspiracy theorists claiming Mark Zuckerberg et al at Facebook had set up the group to test user reaction to the concept.A quick Google to double check confirmed but did get me thinking when I stumbled on an interview with Guy Kawasaki, celebrated marketer, VC, blogger and columnist for the US magazine Entrepreneur. He says if he owned Twitter, where he has a huge following, he’d start charging $30 a month to make it better.Surely we’ve been here before and exhausted the argument? This web 1 rhetoric being applied to web 2.0 experience isn't just archaic it seems almost impossible to make work.Paid for premium email died overnight when Google launched 1GB’s worth for free. Any value add service Facebook, Twitter or any other site attempted to charge for would simply set competitors, or new entries, scrambling to offer the same for free.But then they do say all things are cyclical so perhaps subscription isn't as dead as we thought. Maybe the critical mass of Joe Public has more loyalty (or addiction) to Facebook, and possibly Twitter, than web 2.0 gospel has accounted for?Would you pay to use a social enterprise or access your favourite site? Just as importantly would you consider charging for access/content?