For Prime members only at Amazon, buy two Amazon Dash buttons for $9.98 and get a third Amazon Dash button for free. (The discount applies at checkout when you add three buttons to cart.) Even better, you'll bag a $4.99 Amazon credit after your first press for each button. (That's $15 in credit total if you press all three buttons.) Plus, these orders receive free shipping. Assuming you'll use the credit, that's essentially a $5 profit, although we saw the buttons for a buck each with the $5 credit in July. Deal ends September 17.

Note: Pressing the button will place an order for the button's designated product.