As has been said earlier in this thread the level of competition can be a very significant factor.
Swanage Railway for example has:
1) a Co-Op Store which has a Costa Coffee self service machine literally a stones throw from the station.
2) a Budgens Store which also has a Costa Coffee self service machine a stones throw and half from the station.
3) a Greggs takeaway two stones throw from the station.
4) A Harry Ramsdens two a bit stones throw from the station.
5) About 30 takeaways, fish and chip shops, cafes, pubs, ice cream parlours within a 5 minute walk.