Retailers would love nothing more than to read your mind.
Technology is not quite there, but international fashion brands are using an equally futuristic method to track their customers' buying behaviour.
Five unnamed companies in Europe and the US are using mannequins with embedded cameras that have facial recognition technology to collect data on customers' age, gender and race, Bloomberg reported this week.
The EyeSee, sold by Italian mannequin maker Almax for more than $5000, has a camera in one eye and its manufacturers claim it gets valuable data because it stands eye level with the customer.
The collected data has prompted stores to change their store layouts and window displays, though Almax chief executive officer Max Catanese would not reveal the names of clients.
One fashion company introduced a children's line after the data showed young people were the majority of their customers during the mid-afternoon.
Another company put Chinese-speaking staff at their entrance when the footage showed a third of their customers after 4pm were Asian.
Nordstrom, a US department store chain, said facial recognition systems raised some concerns, while others questioned the legalities.
"It's a changing landscape but we're always going to be sensitive about respecting the customer's boundaries," a Nordstrom spokesman said.
Many big retailers mostly obtain buying data from loyalty cards and could, in principle, use security camera footage to better understand that information, marketing experts say.
"At the end of the day they want to know what's going on inside the consumer's head, and they want to observe their behaviour," said Professor Paul Patterson, from the Australian School of Business at the University of NSW.
Patterson said loyalty cards, now offered by all major retailers, allowed companies to track what you buy, the frequency of buying and the amount you buy.
"In that case, they're capturing actual behaviour.
"What, of course, the supermarkets don't know is what's going on in your head. How are you making these decisions?
"You go to an aisle and you're confronted with six brands of margarine. How to you choose brand C over the other four brands?
"I'm not sure the mannequin is going to [answer] that."
Professor Mark Uncles, also from the Australian School of Business, said it's not known if Australian retailers used footage from security cameras to complement the loyalty card data.
"They're certainly collecting the information, the videos are running. So, in principle they could do it."
Unlike camera footage, which leaves identities and exact demographic information unknown, loyalty cards can tell retailers exact demographics and match that profile against purchases recorded at the check out, Uncles said.
"So this is giving you information about what customer x buys, in terms of the product category and the brand.
"That's very rich behavioural information and you can do that for everybody who has got a loyalty card."
The pitfalls of retailers relying on information from the loyalty cards is that only some card holders may actually use them, resulting in skewed data, Uncles said.
"Lots of people acquire them. They don't always use them. They forget, or they lose the card.
"The attrition rate would be quite high."
- Sydney Morning Herald