We’re predicting that retail media is the third big wave of digital advertising, following in the footsteps of search and social. Here’s what you need to know about one of this year’s biggest topics:

1. Retail media is growing fast.

According to our forecast, US digital retail media ad spending will grow 31.4% to reach $40.81 billion this year. By 2024, the total will grow to $61.15 billion, making up nearly 20% of digital ad spending.

2. But not all growth is equal.

Instacart will experience the largest boost in retail media ad spending this year, growing by 44.5%. Walmart, Amazon, and Etsy will also see positive growth, while eBay’s retail media ad spending will decline 12.6%. To keep that edge, Instacart, Walmart, and Amazon have all made investments in their ad business this year.

3. Don’t discount in-store.

The top three retailers by US monthly audience reach (both in-store and digital) are Walmart, Target, and The Home Depot. The number of in-store shoppers exceeds digital shoppers at each retailer, indicating that in-store media has a bigger reach. But it also means digital has more room for growth.

4. A variety of retail categories are getting in on the game.

Eighty-two percent of US advertisers plan to increase their spending levels with retail media networks this year, with jewelry and luxury, consumer electronics, beauty, and consumer packaged goods brands leading the charge. Just about everyone wants in, so it’s smart to get started now.

5. The benefits are plentiful.

The most important benefit that retail media offers brands is a closer relationship with retailers, followed by creative services, access to owned and operated media/properties, first-party sales data, and personalization opportunities through creative. For retailers, media networks offer a new revenue source and the opportunity to gather data on customers.

This was originally featured in the Retail Daily newsletter. For more retail insights, statistics, and trends, subscribe here.