I bought the pebble after suffering from Insomnia one and off for a couple of year after my twins were born and completely messed up my normal sleep patterns. I would have problems getting to sleep, staying asleep and waking up early. In some cases I would have literally no deep sleep constantly checking the time and getting more annoyed that I can't sleep. The pebble goes under your pillow and effectively makes you feel tired after about 5 minutes, I normally read for 5-10 mins until I fall asleep. It does not work absolutely 100% of the time if I have too much coffee or alcohol etc but with the right supplements and bed time routine it can make a big difference. I now rarely have a problem getting to sleep and get a solid 6-7 hours on average.