On holiday in Cornwall this summer we visited Polperro, a Cornish fishing village so archetypal that it featured in Ptolemy Dean’s BBC programme The Perfect Village. As the programme synopsis says:

On the surface, Polperro looks as if it hasn’t changed for centuries, but in fact it exemplifies a delicate balance between the tourist village of today and the fishing village of yesteryear. It could, without careful management, slide into being a fishing village cum heritage theme park – a victim of its own success and adaptability.

As we wandered down streets where every fisherman’s home was now a holiday let, I felt there was a lesson for social web and mobile services at risk of being overwhelmed by their own success as destinations. So I stuck the name “Polperro” in the title of a blog post and left it there to see how it got on. Until now.

When I first arrived on Twitter it felt small enough to be that fishing village – a fairly homogenous group of the people so that even the river of recent public updates felt like an intimate conversation between friends. How a service like Twitter copes with the inevitable influx of visitors if successful is a matter of debate.

So here’s my thought on the matter prompted by the whole Polperro experience: the ability of the service to absorb newcomers varies massively depending on what the service is for, and what attracts visitors to it.

From Blackpool to Ibiza to Myspace, there are some destinations that positively revel in the crowds (and conversely feel somewhat forlorn without a critical mass of people).

On the other hand there are others – Venice? Alton Towers? Flickr? – where the mass of people is an inconvenience, but the content so compelling that we’re willing to put up with the crush.

And then, the most fragile of all, the places whose main or only selling point is unspoiltness – places we go to witness or take part in something special, but just by being there we destroy whatever that quality was. The perfect village? The perfect bar? Twitter?

Update 05/02/2009: Cait says it’s Not like it was in the old days.