We thought it was time to understand multichannel shoppers better, so we asked more than 5,000 of them in the US, UK and France how they made purchases in 20 product categories.

Ten of these product areas were key grocery store categories (from cereals to skincare) and a further four would often be sold in grocery retailers with a significant general merchandise offer. The results were, in some cases, surprising.

Firstly, almost everyone (86%) is multichannel shopping. Delve deeper and we find out that, contrary to popular belief, multichannel shoppers do not spend more than their single-channel shopper counterparts.

They do, however, spend more time browsing, so they can be significantly more valuable to individual food and drink retailers. It is for this reason that retailers and brands must now, more than ever, focus on ways to engage effectively with shoppers across multiple channels.

This means understanding shopper behaviour based not only on channel and category choice, but also on individual shopper motivation. Sophisticated multichannel shoppers have very clear motivations for using different channels, the roles they want different channels to play, as well as who is delivering a good experience in-store compared with other media, especially online.

They are also clear about when different channels are most relevant to them. In particular, the higher the perceived risk in a purchase, the more likely they are to use multiple channels for search and, ultimately, purchase.

So, is engaging highly promiscuous shoppers across multiple channels all but impossibly complicated? Well actually, no.

Shopper-derived insights to understand the roles of different channels when they're used and how they're used for different products and purchase occasions provide the building blocks for effective shopper engagement. Combine this with a marketing partner that can create compelling communications across all channels, and the shopper engagement battle can be won.

Dr Alan Treadgold is head of retail strategy at Arc Worldwide the brand activation arm of the Leo Burnett Group.