Total sales, including both in-store and online revenue, are expected to increase by 3.5 to 4% to between $961 and $965 billion from last year. Retailers might find this projection disappointing, as last year’s sales showed a 5.2% increase in total sales.

“Online sales continue to be a growth channel, but more importantly, we’ve passed the tipping point where online and mobile engagement play a greater role generating sales in the physical store—where more than 90% of retail sales occur—than in digital channels alone,” said Rod Sides, vice chairman, Deloitte LLP, in the report.

While the majority of holiday sales still take place in-store, Deloitte projects that online research and discounts will influence two-thirds of every dollar spent in brick-and-mortar stores, totaling $434 billion in spending this season. For example, more shoppers are checking their phones while shopping in stores to compare prices for items.

The big question will be how much online shopping will erode in-store sales this year. In the 2014 holiday season, online sales jumped 15% to $53.3 billion, according to data from Comscore. Cyber Monday alone brought over $2 billion in sales online.

But it looks like brick and mortar retailers are prepared. Macy’s (M) announced this week that it would hire slightly fewer holiday season workers, but will allocate more workers this year to e-commerce operations.

For more on how the way we shop is changing, watch this video:

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