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Airtime top-ups drive increased survey participation

Send instant mobile top-ups to 165+ countries. Use them as a survey incentive — and watch your completion rates skyrocket.

Recharge mobile phones of hard-to-reach populations globally

Many powerful features specifically designed to improve data collection with incentives and rewards.

International coverage

Send airtime top-ups all over the world. 165+ countries and growing.

Personalized amounts

Send airtime top-ups in bulk, with a different amount per participant.

Bulk incentives

Save time by sending airtime top-ups in bulk to all of your participants.

Local currencies

Send airtime top-ups in your audiences’ local currencies (pay in USD).

Failure actions

Configure actions to trigger if a top-up fails. For example, automatically send an SMS to the recipient asking for another number, and have the top-up sent to it.

Repeat automatically

Set up your campaign so that top-ups go out at regular intervals on specific days of the week and at set times, saving you time and effort.


Conditional logic

Configure your campaign so that top-ups go out only if specific conditions are met, e.g., the respondent answered at least five questions.

Send top-ups via API

Integrate airtime top-ups into your processes, using our airtime top-up HTTP API. It solves many hurdles that arise when sending top-ups to developing countries.

Success actions

Configure actions to trigger instantly after a top-up succeeds. For example, send an SMS notifying the recipient that the top-up was from you.

Real-time reports

Download your reports immediately and check if someone didn’t receive their top-up and the reason.

Contact subscriptions

Subscribe contacts from other running campaigns to your airtime top-up specific campaigns.

Campaign scheduling

Schedule your airtime top-ups to go out when you want. You can even set a schedule like, “Next Tuesday, at 8am Cambodia time.”

How Johns Hopkins University experiments with airtime top-ups in its public health studies in Colombia, Bangladesh, and Uganda

When conducting major public health surveys in Colombia, Bangladesh, and Uganda, Johns Hopkins University’s Bloomberg School of Public Health (JHU) runs different experiments to understand how and whether airtime top-ups succeed at incentivizing citizens to complete surveys.

In these studies, JHU uses random digit-dialing (RDD) to reach out to millions of random citizens to take IVR surveys, SMS surveys, and WhatsApp surveys. In one RCT (randomized control trial), the JHU researchers wanted to understand whether sending a small airtime top-up before a survey — as proof that the incentive offers for completing the survey was real — would increase completion rates.

The first random group of participants was sent a small airtime top-up incentive ($0.25). If the top-up was successful, the person would then immediately receive a call with the IVR survey, which would start off by telling the recipient that the top-up they just received was from JHU and that if they went ahead and completed the automated phone survey, they’d receive another $1.00 airtime top-up.

The second group did not receive a mobile recharge in advance. They simply received the IVR survey call, which began by informing them that they’d receive $1.25 (same total incentive as the first group) if they completed the survey. The third group was a control group. They received no airtime incentive, just the IVR survey.

Although JHU has not yet reported on these experiments, you can read JHU’s recently published article in Oxford Open Digital Health about other airtime experiments they ran using engageSPARK, as well as the results of how their IVR surveys in Colombia (powered by engageSPARK) compared with those of a nationally representative household survey, published in BMJ.

“engageSPARK enables us to send massive numbers of public health surveys. We get millions of data points in real-time and are able to complete our research very quickly. The platform is really powerful, yet easy-to-use, making any layperson feel like a techie!”

Dustin Gibson

Assistant Scientist, Johns Hopkins University Bloomberg School of Public Health

Top ways organizations use engageSPARK’s airtime top-ups

Incentives for survey completion

Non-profits and research organizations encourage survey participation and completion using airtime top-ups

  • Send airtime top-ups beforehand to ensure participants can send SMS or call in.
  • Tell your audience about incentives at the start of the survey to get a higher completion rate.
  • Automatically reward your participants after they’ve answered the last survey question.

Reimbursing pre-paid credits

Top universities use airtime top-ups to make large scale studies more inclusive.

  • Universities may reimburse participants for airtime spent on SMS or voice calls.
  • If done ahead of time, this makes sure all participants have enough credit to fully complete the survey — and it removes a potential bias.
  • Top-ups can be sent even to the most remote locations, helping you reach a wider and more diverse audience for your studies.

Cash transfer programs

NGOs use airtime for small-denomination cash transfer programs.

  • Pre-paid credit is used to pay for things in some low- and middle-income countries (LMIC).
  • In these countries, NGOs use airtime to support beneficiaries as part of cash transfer programs.
  • Personalize bulk airtime top-ups so each person receives a different amount, as necessary.

How airtime top-ups work together with engageSPARK surveys

1. Add your contacts

Upload all of the contacts to whom you want to send airtime top-ups. Note that all selected numbers need to be pre-paid in order to receive the top-up.

2. Build your survey

You can integrate airtime incentives into every type of survey on the engageSPARK platform: the “Send Airtime Top-up” action is universally available.

3. Select amount

Send the same amount to all participants or upload a list of different amounts for each contact. We’ll make sure the right amount gets to each person.

4. Send instantly

Contacts will receive the top-ups in their local currency almost immediately after sending —and you’ll see the results in the reports in real-time.

Why choose engageSPARK?

Respondents don't need a smartphone

Your participants can receive top-ups on any mobile phone, even a basic phone. They don’t need an internet connection or a smartphone.

Integrated with telcos globally

We’re connected with mobile operators globally, so you can send top-ups to people in 160+ countries — without needing to engage with phone companies.

Exceptional customer support

Our global support team goes above and beyond to help you succeed. Time and again, our clients highlight that our support sets us apart.

Easy-to-use, fast and powerful APIs

Easily integrate campaigns with your server or any CRM. Use our APIs to trigger airtime top-ups directly from your server or to push results into your CRM.

Trusted by the largest organizations worldwide. Used in 180+ countries.

Want to know more about engageSPARK’s Airtime Top-ups?