The game is changing when it comes to buying groceries: The pool of consumers who purchase groceries digitally is expected to jump from 19% in 2016 to 31% in 2017, according to an eMarketer survey of more than 500 internet users. Rachel Kucan, my fellow marketing consultant, and I have recently discovered some interesting insights that we think will be valuable when creating your marketing strategy. In all of retailing, customer expectations around communication has never been higher. Grocery delivery - that is, getting your groceries on your doorstep at the time you want - is no exception. Although there are many players in this field - from brick-and-mortar-turned-delivery businesses, to tech companies getting a piece of the pie, there is only a handful of services that own the customer experience end to end. With the right customer focus, strategy, and technology in place, creating a loyal following for your delivery program will come easily.

An Untapped Market

Although delivery isn't a new idea, grocery delivery with a digital element is new and growing quickly. It is an untapped segment with only 3.8% of grocery buyers currently using a subscription or delivery service. But it's also a segment that's gaining traction: Some 80% of shoppers who bought groceries online in 2016 plan to do so again this year. That's an exciting place to be, if you ask us.

Tech Disruption

To meet this need, the most common entrants are either grocery stores taking a page from the tech-world manual or tech companies recognizing an industry that could use their resources. Ultimately, think Kroger or Walmart launching their own delivery services versus Amazon creating a grocery subsidiary, Amazon Fresh. Between these two are third parties like Instacart or even Google Express, which provide their tech services to brick-and-mortar grocery chains. Outside of these confines are the overall disrupters of grocery shopping, meal-prep kits like Hello Fresh or Blue Apron.

Mobile Communication

After auditing a handful of brands, both grocery-derived and tech-derived, we noticed a trend that fits with current marketing behavior, but maybe isn't the best fit for this type of service. Almost all communication between grocery services and consumers relied heavily on email messaging. Some companies even focused solely on email, and never sent a single SMS or push message. However, this on-the-go type of service - that is, grocery delivery - would clearly benefit from messaging that meets shoppers wherever they may be. The known advantages to mobile are its knack for efficiency and timeliness - both elements that would only improve a delivery experience.

The Recommendation

For companies thinking of launching a delivery program, we have put together a list of what to do, what not to do, and one foundational rule to follow.

The foundational rule you must get right is this: Clearly communicate the delivery window and do so in the right channel. The best case scenario would involve regular updates of confirmation, fulfilment, and delivery within the channel that the customer ordered or directly chose as his or her preference. Given that 68% of shoppers would be "somewhat" or "very" likely to switch grocers to one with a better online shopping experience. it's important to give your customers the best experience possible throughout the ordering process. In our research, there were some clear winners when it came to communication on the day of delivery.

Instacart sent four push messages during the delivery day: a delivery reminder, an order update, an on-its-way notice, and a post-delivery survey. It was simple and easy to watch the order though the process and ensure that we were ready for delivery.

The ones that got it wrong? One delivery company gave a window of 24 hours. Yes, that's right - they wouldn't even rule out a 3:00 a.m. delivery. This service wasn't making my life easier. The groceries arrived at 11:00 a.m. but the stress of not knowing the delivery timetable caused me to rethink ordering from them again.

What's worse than an ambiguous delivery time? Not hitting the time you promised or telling customers something they already know. One grocer promised a delivery between 9:00 a.m. and 10:00 a.m., but called at 9:50 a.m. to say that they would be almost an hour late (although I give the grocer points for the call). Finally, a third service sent a push notification to signal when the groceries would arrive - but the push notification was sent two hours after delivery.

Moral to the story: If you can't do it right, don't do it at all. Customers aren't loyal to a service yet, so determine what you can do, and do it well.

The first purchase is only the beginning. There are a myriad of tactics to create loyal customers. Customer referrals can drive acquisition and retention. Special offers (like free add-ons or free delivery) can help bring back those on the fence. But be careful with too many freebies. Eventually the freebies have to end. Ultimately, when you're focused on helping your customer, you will create lifelong customers and beat the competition.

When it comes to delivery, the playing field is wide open to both brick-and-mortar and technology-first companies. To reach the on-the-go, efficiency minded consumer, leveraging mobile push and SMS to keep in contact is a smart approach. Be relevant. Be timely. Be helpful.