How do you market a store with no budget?
Be findable and be specific. Answering the questions your buyers actually type, in a category narrow enough to own, is the only growth channel that does not require money.
In more detail
It is slower than advertising and it accumulates, which advertising never does. Add one owned channel — a list built at the order — and a store with no budget has a way to reach people twice.
What to do about it
Attribution is harder than the dashboards suggest. A customer sees six things and the last one takes the credit.
The cheapest customer is the one you already have, and most budgets are spent as though that were untrue.
A channel that works at small spend often stops working at large spend, because the cheap audience runs out first.
The mobile app angle
Push notifications sit on the owned side of that line, which is the whole commercial argument for an app.