Along with having the right wavelength, you have to have enough strength to deliver the negative electrons into the hair follicles. If somoene has a lot of inflammation on their scalp (usually if the person has a inflammation under their chin (calcification, globulin, and other toxins causing inflammation) they are probably going to need more session time or have a stronger laser. It is not just about having the entire scalp surface having full coverage. It is the total amount of energy that is being delivered. You can have a three 40 mW diodes shining on the scalp or twenty-four 5mW diodes shining on the scalp. It is the same exact thing.
If the lasers are very low powered (5mW), and I need more energy delivered to the hair cells, the sticker can emit its frequencies that the laser, even if the laser is so dim that you can barely see the laser, it will still pick it up and I can feel the energy. The stickers seem to go against the greatest depth theories.
Notice: If a laser has 500mW weather it be a single 500mW diode or 100 5mW diodes, it is classified as a medical laser. Some people may want a laser that is stronger that delivers the energy quickly and others may want a laser that is less strong that they have to use or wear longer. Depending on the starting voltage of the body and scalp, one over the other is usually preferred but will vary depending on the person. One laser strength might be better for one person and too strong or weak for another.