Yes they pay as long as you qualify for them. You won't always qualify depending on your demographics (ex. age, state, marital status, etc.),and even if you do qualify and complete a survey, every now and then it still may not credit to your account. It happens. Persistence is the key and there is no strategy on doing surveys. Just be honest with your answers and make sure when you complete one, leave that page open for at least 5-10 minutes. Then check your account to see if you got credited.