The National Retail Federation (NRF) today announced it expects retail sales to hit $616.9 billion, a 4.1 percent growth over last year’s holiday season. The NRF also predicts that retailers will hire between 725,000 and 800,000 seasonal workers this holiday season (last year, they hired 768,000, a 14 percent increase over the previous year).

Why will there be an increase?

NRF’s holiday sales forecast is based on an economic model using several indicators including, consumer credit, disposable personal income, and previous monthly retail sales releases. It now includes the non-store category (direct-to-consumer, kiosks and online sales.)

“Though we have only seen consumer income and spending moderately – and erratically – accelerate this year, we believe there is still room for optimism this holiday season,” said NRF Chief Economist Jack Kleinhenz. “In the grand scheme of things, consumers are in a much better place than they were this time last year, and the extra spending power could very well translate into solid holiday sales growth for retailers; however, shoppers will still be deliberate with their purchases, while hunting for hard-to-pass-up bargains.”

How does this growth compare to previous years?

According to the NRF, holiday sales on average have grown 2.9 percent over the past 10 years, including 2014’s estimates. This would mark the first time since 2011 that holiday sales would increase more than 4 percent.

What percentage of annual retail sales take place during the holidays?

The NRF estimates that this year’s November-December sales will represent approximately 19.2 percent of the retail industry’s annual sales of $3.2 trillion. “Retailers could see a welcome boost in holiday shopping, giving some companies the shot in the arm they need after a volatile first half of the year and an uneventful summer,” said NRF President and CEO Matthew Shay.

What about online sales. How much will they grow?

The NRF’s online retail website Shop.org forecasts online sales to grow between 8 – 11 percent over last holiday season to as much as $105 billion.