Interestingly, in writing this, I contacted James and Anette at Square Mile to ask about whether this issue is active in London (considering I was writing for a UK publication). Here’s what James told me:
Wifi usage here hasn’t had the same impact on cafes in London that it has in the states. Whether a cafe offers wifi has relatively little effect on its success and we have a lot fewer people sitting in a cafe working. Maybe our British reserve makes us think work should be hidden away in an office.We’ve generally been more ‘to have in’ than to take away as a nation, though that has somewhat changed in the last few years. You are as likely to find someone hogging a chair in Starbucks for 2 hours with a book as with a mac. This – I think – is a very good thing! I certainly would actively discourage any serious cafes (who might ask my advice) from doing. Space is too premium (like NY I guess) and it isn’t enough to draw people here into a cafe.