In general, the
add to cart button is meant to enable users to buy multiple items with a single checkout action. When you enabled buying one ebook at a time, this option was redundant, however, now it does enable:
- purchasing multiple items using the same payment method and same shipping address (or same email address for download links)
- reducing shipping costs by shipping items together (not relevant to ebooks)
- changing items if you find something your prefer e.g. a bundle of a series of books instead of two separate books
You could emphasize the
add to cart option by giving it a button instead of a link and emphasizing the difference between the two with different icons (e.g. full cart + check mark for
buy now vs single item in cart for
add to cart), the question is how commonly do people want
add to cart vs.
Comparing with other sites you can see on eBay:
and on Amazon:
So clearly, both sites treat
add to cart and
buy now as options of equal importance.
You could go with two buttons underneath each other as the other sites do:
download bmml source – Wireframes created with Balsamiq Mockups
Or side by side:
download bmml source
The second option, however, do make the
share for discount action seem too dominate in my opinion.
The cart view is a good experience, however, you should make sure it has an edit option (e.g. for removing items, changing quantity) and that it can be refreshed (ideally automatically) if cart is stored on server (so if a user adds an item via a different tab, current tab will reflect the change). You could do this by changing the cart title into a link and/or adding an edit button/link to it.
You should also consider launching a few options and A-B testing them to see which is preferable with your users.