Can only echo previous posters.
The reason these places fail is two-fold ..... one, Mums come in, buy one coffee and stay for hours, two, they get grubby & unpopular as kids grow older.
Eat Play love are doing so well, as others have said, beacuse of their size. The first time we went the food was appalling, but we went back because of the classes they ran, and because the kids begged me ! All subsequent visits have been great, the food has improved, they've gone from strength to strength and I'm so pleased for them - they've done wonderfully.
I do fear that the new childrens cafe / play area proposed in Battersea park will damage their trade a little though. I read in an edition of Southside that they're planning a (brilliant sounding) cafe, with outdoor area and toys for little ones where the one o'clock club currently is. I really hope this doesn't impact on the great job all at E,P,L have done so far ......... but it's exactly this kind of thing that makes these businesses survival harder in reality than they seem at the outset.
How is that sweet little bookshop over by Clapham Common doing, does anyone know ? Underneath the Greenwood Tree or something like that ? I had high hopes for that.
Anyway, to summarise
:
Offer something to offset the one-coffee brigade, entice with classes for instance to keep them there longer / stay for lunch (if so, make food decent at least).
Have a good large area, multi-functional (able to hire out for parties, big enough to allow your classes to run separately from the main cafe area). This is hard to find with low overheads.
Ensure a lack of competition locally.