Sometimes, you may want to show your clients a list of products and services that you offer, and let them make purchases; similar to a retail store.
Here are a few example scenarios:
After a wedding, you can send add-on options to your bride and her family so they can purchase parent albums or thank-you cards.
You want to email your clients with a holiday gift certificate promotion and let them choose from several denominations of gift certificates available.
You offer a gift registry to your bridal and newborn clients, and you want to give them a link to share with their family and friends so they can purchase gift certificates in varying amounts.
After a networking event, you want to share options for headshot and portrait session packages to everyone you met, and let them purchase one of the options right away.
Sometimes, you may not necessarily want to have these purchases associated with a set of images. For the wedding add-ons, for example, the products don't necessarily have to be tied to the wedding images. The gift certificates, as another example, don't necessarily have to be associated with any images, since it'd be a public shopping cart option.
Sprout Studio does have public price lists, but your clients cannot purchase from those public price lists. They are for illustration and informational purposes only.
However, a workaround that allows you to have a public shopping cart functionality would be to create a gallery with a single "instructions" image and add products and services available for purchase from that gallery.
Here's an example video of one in use:
Here are two sample "instructions" images you can use, as well as an Adobe Illustrator file that you can download and edit.