MIAMI (CBS4)- Paper or e-mail? That’s the new question consumers may be asked the next time they’re paying for something and the clerk offers a receipt. But aside from being a convenience, some experts say the new option may be a hindrance to privacy.

Customers are now being given the option to have a receipt electronically sent to their inbox. But if you opt for an e-receipt, what else could start popping up in your e-mail?

Paperless receipts are the wave of the future. Major banks e-mail customers ATM slips, mobile vendors send e-receipts to your inbox and the number of retail stores offering electronic invoices is exploding.

“More customers are opting to receive their receipts via e-mail because it’s saving on paper and it’s also more convenient for them,”   business manager Stephen Macary said.

Macary said he loves e-receipts. He manages a fleet of company cars, and when one needs an oil change the repair shop e-mails him the invoice.

“It gets you the information in a timely manner, and you’re able to view the documents pretty much right away,” he said.

But shortly after he gave the shop his e-mail he discovered that surveys, coupons and reminder notices started popping up.

“All these vendors capture information; they’re going to capture it for e-mailing you something,” he said.

And he’s not alone.

It turns out a lot of other “paperless customers” end up getting swamped with junk mail too.

That’s because some businesses make big bucks by filling your inbox with offers and sometimes even selling your information.

“Nothing is as profitable as your own in-house mailing list,” he said. “When you give that information you’re building a store’s mailing list.”

Consumer advocates warn that some retailers take that info and build profiles about who you are, your age and your buying habits.

Privacy experts say before you opt for an e-receipt find out how the business keeps your info secure and if they sell it.

“These e-mail addresses can now be as valuable as a credit card number because they have huge data insights into the individual transactional behavior and product interests.”  

Privacy experts recommend setting up a separate e-mail account just for e-receipts to keep your regular account from getting too much junk mail.

And don’t forget to back them up, experts warn, especially if you need them for tax purposes.