A town built around a workshop
The Eastern Bengal Railway opened its workshop and station here in 1863, and the town grew around the railway township. Kanchrapara became a municipality of its own in 1917, when it was separated from Halisahar. The workshop served the defence department in the Second World War and, after electric traction reached eastern India in 1962, became a base for overhauling electric locomotives and EMU coaches.
For most shops in a township like this, customers are neighbours who come back: the same families, schools and clubs, season after season. That makes most of their WhatsApp traffic replies and updates to people who already know them, and it makes asking for consent to offers easy: ask the customer at the counter, and record the yes.