The first lesson about ads that sell is to follow the action. You, as an advertiser, must go where others are. You could be a true explorer and find your own success alone, and you may wish to do that to some extent. However, in addition to that strategy, until you find your own areas where success comes more easily, you should go where others are advertising now. The first measurement you must assess before you spend much effort or money is whether others are being successful in that medium.
Success breeds competition.
Competition gets the medium noticed, which brings more potential clients, which leads to more success. Success is contagious. If your offer is not bringing you success, examine where you are placing your offer. I have never caught a fish in a tree, although I have strategically placed a few lures there. I had all the right gear.