The Add To Cart URL is usually all you need when it comes to listing your Digital Product For Sale, you can share it in a million ways. For example you could include it in a hyper link
<a href="ADDTOCARTURL">Buy eBook</a>
Or it can be an image
<a href="ADDTOCARTURL"><img src="BuyButton.jpg"></a>
You can even share the URL on Social Media Networks and it will work.
You also have the option of copying and pasting the Product Form HTML which works with Digital Products Seamlessly.