And so the lesson is this: it doesn't really matter what you're selling; you just have to think about who is your customer, and what are the messages that are going to get them to change their behavior.
و درنتیجه درس اینه: اینکه چی داری میفروشی واقعا اهمیتی نداره تو فقط باید به این فکر کنی که مشتریت کیه و پیامها چی هستند اون قراره که رفتارشون را عوض کنه.