Americans' shopping habits are quickly changing, which means retailers and tech start-ups are racing to make over every part of the industry, from the weekly grocery trip to putting together a weekend outfit. And while many of the new offerings - mobile payments, new methods of delivery - are centered on online shopping, many others are seeking to simplify the way we find and buy products in stores.
"The retail sector is going through a fundamental change as companies find new ways to use data and intelligence," Greg Jones, director of industry solutions for retail at Microsoft, said at the National Retail Federation's annual conference this week. "Artificial intelligence is now a part of the fabric, and we're seeing faster adoption of new technology than ever before."
So how exactly will these new technologies shape the way we shop? Here are five trends to watch.
1. Prices that change by the hour.
If you're an avid online shopper, chances are you've noticed prices on specific products - a box of tissues, say, or a blender - change at what seems like a flip of a dime. Now that same sensibility is making its way to in-store retail.
Digital-price displays at grocery powerhouses like Kroger now allow retailers to make sweeping changes to their prices in one go. Whereas adjusting prices or marking down weekly specials would normally take hours, if not days, new technology makes it possible to change thousands of prices with the click of a button.
"With this you can update 20,000 prices in a matter of 1 or 2 minutes," said Kevin Fessenden, research and development manager for Kroger. "In the paper world, that would take three or four days."
Kroger, the country's largest supermarket chain, has swapped out paper price tags with digital screens at 17 stores, with plans to expand to 130 by the end of this year. And although store managers are now using the system to make routine price adjustments, Fessenden said the technology could also be used to make adjustments based on supply - or demand.
If a particular store is down to two bottles of tomato sauce, for example, a manager could raise prices until the next shipment arrives. Or, Fessenden said, "if we have a lot of cereal, we could decide to do a flash sale."
2. Digital mirrors to help you visualize new outfits, lipstick or sunglasses.
Not sure if red lipstick's your thing? Or whether those tortoise-shelled glasses look good on your face? Now you can ask your mirror.
Digital mirrors by Memoni, which are already used by retailers like Sephora and Neiman Marcus, allow shoppers to try - and get feedback on - makeup, glasses and other wares. If you're in the market for a new pair of frames, you could try on different styles, take short 360-degree videos and compare your options side-by-side. Or perhaps makeup is more your thing. Memoni's mirrors allow you to record tutorials by makeup artists (so you can recreate the look the next morning) and see how your blush or lipstick would look in different lighting. Still not convinced? You can send images and videos from the mirror to a friend for instant feedback.
3. Robotic shopping carts ... or no carts at all.
Meet Dash, a robotic shopping cart that imports your shopping list, guides you to each item and allows you to check out with the swipe of a credit card. After you've finished shopping, it follows you to your car. And the best part? Once you've unloaded your groceries, Dash will automatically find its way back to a docking station.
Dash's predecessor, called Budgee, was created by Five Elements Robotics to carry around items for the elderly, disabled and others on the go. Soon after, co-founder Wendy Roberts says she began fielding calls from retailers.
"They all wanted to know, when are you going to create something for us?" she said. "They had a very specific list of requirements."
Among them: The shopping cart had to hold 250 pounds, collect data about users' shopping habits and accommodate online orders. And instead of following around the user, it had to be able to lead shoppers through supermarket aisles.
The cart is going into production in the coming weeks, and Roberts said she has been in talks with companies interested in using the technology.
Elsewhere at the conference, the start-up Xenia had partnered with Microsoft to come up with an entirely different approach: A cart-less shopping experience, in which consumers simply use their phones to add items to a virtual cart as they walk through the store. At the end of their trip, they can choose to have their purchases handed to them or mailed to their homes.
"It allows retailers to really rethink what their store footprints look like," said Katie Quinola, a Microsoft spokeswoman. "Instead of having 10 products on a shelf, they can just keep one."
4. Technology to help you find better-fitting shoes, and coordinating outfits.
Algorithms are taking over your closet, whether you know it or not.
Companies are increasingly collecting thousands of data points on their customers and using technology to recommend products they might like. Companies like Stitch Fix are using algorithms to send monthly clothing shipments to consumers' homes, while New York start-up FindMine is partnering with retailers like American Eagle Outfitters to help them provide personalized outfits around every item they sell. Can't figure out how to wear that new denim jacket you bought? You can text a photo to American Eagle via Facebook Messenger, and FindMine will send you outfit pairings within seconds.
"Customers will buy 200 percent more when they see a whole outfit," co-founder Michelle Bacharach said. "With algorithms, we can automate what is normally a slow and painful process."
Another company using data to make recommendations: Volumental, which is being used in nearly 1,000 shoe stores to help customers' find the right footwear.Customers step onto a 3-D scanner, which creates virtual models of their feet and uses the data to suggest shoes based on width, arch height and other measurements.
Eventually, chief executive Alper Aydemir said, that data could also be used to create custom stores on a 3-D printer.
5. Robots that restock shelves and guide you to what you need.
Store owners say that keeping shelves well-stocked and inventory in the right place is among their biggest challenges. Now retailers like Lowe's and BevMo are outsourcing much of that work to robots.
The device, by Fellow Robots, rolls through the aisles checking for misplaced items and empty shelf space. If it sees, for instance, that a store is running low on hammers, it will alert employees to order more.
But perhaps just as important, its creators say, the robot can also answer shoppers' questions and help them find what they're looking for.
"We worked hard to make sure these things are friendly, and that they're a part of the store," founder Marco Mascorro said. "We didn't want customers to look at it and think, oh, there's a machine standing here. We want them to be just another part of the shopping trip."