Incentives are rewards that are paid to respondents for participating in a market research project. There are generally three incentive types, (1) cash, (2) cheque/bank transfer or (3) vouchers/product give-a-ways. In 99% of instances we would always recommend paying market research respondents in cash once they have completed their research (please note this is not a viable option for online surveys and instead vouchers or prizes are usually issued), so in instances of focus groups the market research participants should only be paid at the end of the group (not ‘before’ like most of the other agencies attest to).
From many years of experience, generally if you offer cheque or bank transfer not only will it cause a headache in terms of administration but respondents are less likely to be interested in the research and are also more likely to drop out at the last minute should they have already agreed to the research. Similarly, vouchers or product give-aways are equally frowned upon by respondents and are generally only effective as an incentive if the voucher or product is of substantial value - a good gauge is to consider a cash figure and then add an equivalent voucher/product value of at least 50%, if not 100%.