Most shoppers use traditional paper coupons found in the newspaper when they shop for groceries and other goods.

Almost 90 percent of all coupons redeemed in 2011 were distributed in freestanding newspaper inserts, according to a report from NCH Marketing Services. That study notes that digital coupons, whether print-at-home or electronic, accounted for about 1 percent of all coupons distributed last year in the U.S.

It's safe to say that paper coupons aren't going away, but digital coupons are on the rise. E-coupons are paperless, electronic coupons that can be loaded to a store loyalty card or account via an online interface or phone app. Shoppers click or touch the coupons they wish to use. When purchases are scanned at checkout, the coupons you've selected are deducted automatically. At least, that's what's supposed to happen.

Q: I don't trust these new e-coupons. The big grocery store in our area has a phone app that lets you load the coupons to your card, or you can load them on the store's website. But sometimes the coupon's value doesn't come off when I scan my card at checkout.

I've had bad experiences where the store doesn't want to fix this. Unless you show them the phone app or print out your coupons, they won't do anything. I think it's easier to use paper coupons. What do you do if e-coupons don't work?

A: Oh, the security of a paper coupon! If a paper coupon doesn't scan at the register, a cashier usually can handle the issue quickly. But since you don't see the e-coupon deducted, the first indication that something went wrong takes place when you check your receipt.

If you load e-coupons on a smartphone app, open the app and show an employee the e-coupon. If you don't have a smartphone, print a copy of the e-coupon discounts loaded to your card before you hit the store. If you use e-coupons from a third party, you may need to contact that company. Popular websites such as cellfire.com and savingstar.com offer load-to-card e-coupons for a variety of manufacturers and stores. If you have issues with e-coupons, save the receipt and contact that site's customer service.

Some e-coupons take time to apply.

SavingStar's e-coupons are not applied at the register. The savings are deposited to your SavingStar account within 30 days of purchase. Once savings reach $5, the money is deposited to your bank or PayPal account, onto an Amazon gift card or as a donation to American Forests.

Visit www.jillcataldo.com.