What do you think?
Allow orders without requiring customers to log in first?
Yes? No? Why?
Yes. You want to put as few steps between your customer and your product as possible. Give them the option to login but don't force it if they can order without it.
Also give them the option to sign up after the order is complete with a clear value proposition (see your order history, easily track packages, faster purchases in the future, and even rewards).
That's a great point about following up with a signup. Gives me some ideas... ;)