Where can I find these companies?

It is important to be selective about the survey site that you choose to join.

Look carefully at their terms and conditions and make sure you understand how the payment process works.

Try and see how often they have surveys as it can be frustrating if there are not surveys to complete on a regular basis.

Try and find reviews of other users in blogs or advice websites as this can give you a rough idea of the amount of work needed and the amount of money you can expect to make.