It's not all about the percentage of THC either, but the TYPE of THC too. If you metabolize delta 9 THC by eating it, it turns into 11-hydroxy-THC, which is 15 percent more potent than the delta 9 THC you get from smoking it. Also, when you eat it, you get ALL the good stuff, not just some smallish fraction, and the effects last much longer. Combine the superpotent strains with eating instead of smoking and you have a recipe for massive stonings.