Does Paypal "Buy Now" button triggers webhooks? What's the disadvantage of using the Buy Now button versus a fully integrated payment system in a website selling digital goods?
PayPal buttons trigger webhooks called IPN (instant payment notification). You can define a controller to handle this request and update your database.
The button you put on your web site can include custom fields that will be sent back by the IPN (along with all information sent by default, such a price, etc) , making it easier to identify the payment (such as the identifier of the customer in your application).
I can elaborate and add some code later. Unfortunately I’m on my cellphone right now.
I cannot compare to other methods, as I have only worked with PayPal buttons and IPN, but it’s quite easy to make it work.