I can't add a book to the shopping cart on my phone! What can I do?

This may be happening because you are blocking cookies in the Safari web browser.

To stop blocking cookies in Safari on an iPhone:

1. Open "Settings" from your phone's home screen.
2. Scroll down and tap on "Safari."
3. Scroll down to the "Privacy & Security" section and un-tick the "Block All Cookies" option.