Guest checkout allows your shoppers to checkout without having to create an account. This article discusses the possible values available for the setting 'GuestCheckout' (found in Configuration > Settings)
Important concepts to understand about guest checkout:
Shoppers who checkout as a guest will not be 'registered' customers. Therefore they will not be able to login with their account later, and they will not be able to view their order history for their guest checkouts.
Shoppers who checkout as a guest can potentially be entered in the database with the same email address as another shopper.
The software does not allow two registered customers with the same email address to be created on the same store. In other words email addresses will be unique among registered customers on a given store.
The manner of handling Guest Checkout (also known as 'Anonymous Checkout') has changed with AspDotNetStorefront v10.
The storeowner should decide which of four models is being implemented on his store. (In a MultiStore setup, each domain can be operated independently under different Guest Checkout rules.)
The options are:
1) Guest Checkout is Disabled. Any shopper making a purchase on the store must create an account so that they can log back in and view their order history. On second/subsequent visits to the store, the password will be required to checkout.
2) AllowUnregisteredCustomers. This is the default situation. If a shopper checks out using an email address that is already registered, then a password is required (i.e. the email address being used can't be 'sometimes anonymous'.) However, the owner of an email address that hasn't previously registered can choose whether to create a password (register) or not. Once an account is registered, that email address can never shop anonymously.
3) AllowRegisteredCustomers. If a shopper checks out using an email address that is already registered, he/she is given the option to login and add this order to the history, but can choose to skip the password this time, and log out as a guest. First time shoppers can create a password or check out as a guest.
4) PasswordNeverRequestedAtCheckout. A storefront with this setting will never ask for a password during checkout - every order is treated as a guest order. A shopper can register through the 'create account' process, and can be logged in during the checkout, but the All-In-One checkout will not require login from anyone.
A store owner should give careful consideration to the behavior they choose and can set their preference by navigating to Configuration>Settings and searching for the word 'guest'.