Ancillary revenue on a flight booking is a solved problem for seats, bags and insurance. Mobile data is the newest line on that list and the easiest to add, because unlike a bag it has no weight, no inventory and no airport queue. The difficulty is purely one of timing: offer it at the wrong moment and nobody takes it.
The four moments, ranked
1. The pre-departure reminder, 48 hours out — the best one
This is the email people genuinely read, because they are about to travel and are checking what they have forgotten. It is also the moment the problem becomes real: they are thinking about the airport, not about a holiday in the abstract. An eSIM offered here lands as a solution to a problem they are currently having.
It has a second advantage. A traveller who buys 48 hours out has time to install at home, on Wi-Fi, which is exactly what you want — see what happens when they do not.
2. The booking confirmation
Good open rates, but the trip is abstract and often months away. Works better as a seed than a sale: mention it, link it, and let the 48-hour email close it.
3. Online check-in
High intent, high attention, but you are competing with seat selection and bag upgrades for the same few seconds, and those have higher margins. Worth testing, not worth leading with.
4. The checkout page itself
The worst of the four in our experience. The customer is concentrating on the fare and is suspicious of anything that moves the total. Adding a data plan here mostly adds friction to the booking you already had.
If you only do one thing: put it in the 48-hour pre-departure email, with the destination already filled in. “Landing in Bangkok on Thursday — want data that works when you do?” converts in a way that “buy an eSIM” never will.
What to put in the message
Three sentences is usually enough, and all three should be about the traveller rather than the product.
- Name the destination. You know it. Use it. A generic offer reads like an advert; a specific one reads like a service.
- Say what it replaces. Roaming typically runs $5–15 a day. A week of data usually costs less than one day of roaming.
- Say what it does not do. It is data; their number stays on their own SIM for calls and texts. Being straight about this prevents the support ticket that otherwise arrives from the airport.
Then link to the destination page for the country they are flying to, not to a homepage. The destination list has a page per country with plans and prices already on it.
Why eSIM suits an ancillary slot
- Instant fulfilment. A QR code by email minutes after payment, so it works even for a booking made the night before.
- No inventory risk. You cannot oversell it and you cannot be left holding it.
- It is not a gamble for the customer. Unlike insurance, they will definitely use it.
- It repeats. The next trip needs another plan, and the traveller who had a good experience does not shop around.
Selling flights? Put data in the booking.
Take a commission on every plan your travellers buy, or sell under your own brand through our API. Both work alongside the booking flow you already run.
Frequently asked
Does it work for last-minute bookings? Yes — delivery is minutes, so a traveller can buy at the gate. They just need a connection to install, which airport Wi-Fi provides.
What about multi-leg itineraries? A regional or multi-country plan covers the whole route on one eSIM, which is usually the right recommendation for anything crossing borders.
Can I show prices in the email? Yes. Plans start at $3.29 and per-destination pricing is on each country page.