is it worth enough to do? or complete waste?
You have to be very careful with the product you chose to promote. Most of the time, the “high gravity” products would have so much of PPC buyers that the CPC would have shot sky high by the time newbies enter the field. The best thing to do could be to go the “organic” way by writing reviews and articles. If you are hell bent on PPC, chase the long tail by doing some keyword research. Good luck!