Hook

This is a perfect example of the importance of good design choices when trying to get customers to buy stuff from you. Notice how you could put a cup in literally every single place on this table, but customers aren't taking any of them. They're only taking the cup that's low friction and easy for them to grab. This is the exact same principle that should be used in any circumstance in business, but especially when it comes to online shopping. One of the best historic examples of this is the button known as "continue as guest." When Best Buy added this button, it decreased shopping friction for the customer, which led to a 45% increase in sales that year and made them an extra $300 million dollars with a simple button change. But it's not just about friction, it's also about making a simple, obvious choice for your customer. For example, writing at a 5th grade reading level converts at 12.8% compared to 5.5% for professional level writing. So when you want your customer to take any action, but especially buy something from you, make the decision extremely simple and extremely low friction. And that's how you'll get the most people to opt in. When even if you have the same offer, but it's positioned badly, no one will even take it.
Their other posts in the index, biggest breakout first.