To interview internet users at such a vast scale, we work with a number of industry-leading panel providers such as SSI, Toluna, GMI Lightspeed, DataSpring and OnDevice. These providers manage the relationships with respondents on their respective panels, from the initial recruitment process through to the distribution of invitations to take part in one of our surveys. In some countries, these partners will also engage further panels to help fulfil our sample needs; practically, that means our respondents are typically sourced from between 2-5 panels in the majority of markets.
Although each panel provider will have its own precise systems in place, they will typically be inviting people to sign up for their panels via online ads, sponsored posts, online messaging and partnerships with sites. Anyone who expresses an interest is then required to undergo a joining process, which involves verification of their email address and submission of basic demographic information (which would normally include metrics such as age, gender, location and so on).
Each time we launch fieldwork, we will supply our panel partner(s) with demographic information about the respondents we require in order for our sample to be representative. Part of this involves instructing them on the number of women vs men, the number from each age group, the proportion with secondary vs tertiary education, and so on.