For organic search, you go after keywords that match what people are looking for and build content around them over time. For paid search, every click costs money, so the focus is on keywords that show buying intent. Someone searching "best running shoes" is browsing. Someone searching "buy Nike Air Max size 10" is ready to purchase. Paid search keyword lists tend to be tighter and more specific. Organic lists can be broader because you are not paying per click. The intent behind the search matters more in paid than in organic. So what do you think is the most important factor when selecting keywords for a paid campaign?