Bigger crowds at this year's National Retail Federation conference are a tangible sign of last year's solid growth in the retail industry. About 24,000 people are attending the conference in New York this year, the most in its history.

CNBC About 24,000 people are attending this year's National Retail Federation conference.

Heading into this year, NRF expects growth to slow somewhat, but the industry still expects to outpace the growth of the overall economy. Last year, retail sales rose 4.7 percent and the group anticipates this year sales will rise 3.4 percent to $2.53 trillion.

Meanwhile gross domestic product is expected to increase between 2.1 percent and 2.4 percent, according to the average forecasts from economists.

The changing role of the store and the impact of an even smarter and more demanding consumer will be two of the topics that will be frequently discussed in the coming days at conference panels and on the show floor.