As e-commerce continues to grow, so does the number of fulfillment options available to merchants. In particular, an increasing number of third-party logistics providers (3PLs) have emerged, handling all or some fulfillment operations for merchants who don't see it as a core competency.

Along with the projected increase in holiday spending this season, especially e-commerce, major carriers are all expecting significant double-digit growth in parcel volume before the end of the year.

If you think customer expectations are high overall in terms of e-commerce and direct-to-customer fulfillment, take a good look at the millennial generation. Across a number of studies you see a pattern: a keen desire for the most rapid shipping method possible; free, unlimited returns; and a greater willingness to spend a bit more to get it the same day.

PetSmart has become one of the latest companies to offer same-day delivery - a year and a half behind rival Petco with partner Instacart - via partner Deliv. PetSmart.com says the service is now available in California (Los Angeles, Orange County, San Francisco, San Jose), Las Vegas, Atlanta, Miami, Seattle and Chicago. By mid-November, it will be available in eight additional metro areas for a total of nearly 2,500 zip codes serviced.

In 2015, Cyber Monday generated more than $3bn in online purchases, making it the largest e-commerce sales day in U.S. history. The massive deals and discounts offered during the annual post-Thanksgiving event were largely responsible for the day's extraordinary sales.