Buyer personas are fictional, generalized representations of your ideal customers. They help you understand your customers (and prospects) better, and they make it easier for you to tailor content to the specific needs, behaviors, and concerns of different groups. The strongest buyer personas are based on market research as well as on insights you gather from your actual customer base. 

If you feel like your digital marketing strategy isn't gaining ground like you want it to, it's probably because you don't fully understand who your prospects are. Going through the process of creating buyer personas is REALLY important, because it takes the information out of your head and documents it in a way that is very useful as you continue building out your inbound marketing strategy.