Great article! Excellent point by Matt, precisely why I found this article. I would just add that the CBD percentage in the extract can be significantly lower than even the 20%, but its probably fair to use that to give a rough idea how much CBD might be in an Amazon product, so divide the claimed percentage by 5!. Claims of up to 60% on Amazon are totally ludicrous, any concentration above 20% CBD become darker very viscous and the CBD starts to crystalize in the bottle! You would need to heat the bottle (which can damage the properties of the carrier oil) to re-liquidize! Also beware of Amazon reviews which are notorious for being fake. As author suggests, contact seller for full data sheets or seek a reputable supplier elsewhere that gives full transparency of information up front.