[Clubber]

Delivery is all about logistics. Each product has it's own logistics. Delivering produce is a lot different from delivering books. For the fastest delivery, you need to stock what you are delivering. This is much easier to do with a narrow product range than a broader one.

Having said that, UPS and Fedex, etc are delivery companies. I assume this company is promoting same day delivery, otherwise, why not just use a shipping company.