Interesting idea but curious if wouldn't just be a flop. Many of the students don't have that much money and/or are just cheap. They'll order a coke and sip it for hours while studying at McD or someplace else. Also the problem of wanting to offer a *quiet* study area in a country that loves noise and the problem of how to deal with a group of students that come to study but are obscenely loud as we aren't allowed to shut them up and if we say anything negative they won't be back... and most students will at some time fit into this category be it them or their group of friends.
I'd think for that idea you'd need something *extra* to entice them such as printing services and possibly a couple computers for doing specific things like power point and presentations. Could even mix that up with a few installed training programs for some computer basic programs and training programs depending on the bigger mix of students you might get.
The worry is having 20 seats taken for 6 hours late at night all ordering a 25p cheap drink or sometimes only one in the group orders something!