The reward marker will occasionally need to be used with a food reward to prevent the behavioral response from extinguishing. Research has shown that rewarding every time a behavior occurs actually creates a reduction in the behavioral response, once it has been learned. Reward the behavioral response, on average, every seven times the dog responds with the behavior, but vary it. Sometimes you give the reward the third time he responds with the behavior, sometimes the ninth time, sometimes the second time and so on, averaging out to about every seven times. You don’t have to worry about counting, keeping track or be super precise with the 1:7 ratio. Using a variable schedule, averaging approximately once every seven times, is by far the best system.