The Amazon Dash Button was announced just before April Fools Day, but it was an actual product rather than an April Fools joke and they are now available to buy.
Amazon are offering the Amazon Dash Buttons for Amazon Prime members, the button is designed to let you quickly buy a single product from Amazon.
For example Amazon offers a dash button for laundry detergent, you are supposed to place the button on your washing machine and when you run out, you hit the button and it adds the product to your Amazon cart.
The dash buttons are available for $4.99 each and you can find out more details over at Amazon, whether they will be popular remains to be seen.
Source The Verge