A new site opens with free charging for a fortnight. It is busy. The fortnight ends and it is empty. The operator concludes the site is bad. The site is fine — the promotion recruited people who wanted free charging, not people who wanted that site.
What a promotion is for
Exactly one thing: getting a driver to try something they otherwise would not, in the expectation that the experience is good enough to bring them back at full price. Anything that does not serve that is a price cut with a marketing label.
Four structures that survive their own end
| Structure | Recruits | Risk |
|---|---|---|
| First session free, once per driver | Trial, not habit-of-free | Low — it cannot repeat |
| Wallet top-up bonus | Commitment, and float | Low — the money is already yours |
| Off-peak rate, permanent | Load shifting, which you want anyway | None — it is a tariff, not a promotion |
| Referral credit to both sides | Drivers who already like you | Moderate — cap it |
Note what is absent: blanket time-limited discounts. They are the only structure on the list that teaches drivers to wait for the next one, and once that lesson is learned it is very hard to unteach.
The off-peak rate is not a promotion
It is worth separating. A permanent cheaper window is a pricing decision that shifts load off your peak and possibly off your demand charges. It has no end date, so it creates no cliff, and drivers who use it are behaving exactly as intended rather than waiting for something.
Measure retention, not redemption
The metric for a promotion is the share of recruited drivers who return and pay full price within sixty days. Redemption count tells you the offer was attractive, which was never in doubt.
Run that number once and most promotional budgets get reallocated — usually toward reliability, because the drivers who did not come back mostly did not come back for reasons unrelated to price.