The Curse of the $4.14 Text Message

Increasingly, fine print means companies don't always need you to enter billing information to begin the start of a long and profitable (for them, at least) business relationship. All it takes is a single click of the mouse or tap of your cellphone keys — the equivalent of an electronic signature. "There's usually a 'By completing this action, you're bound by and agree to the terms of this contract,' clause," says Edgar Dworsky, editor for consumer advocate Mouse Print.

Scarier yet, you may never receive an invoice. More fine print enables the company to access your credit card information through a third party, say, your cellphone provider or a partner site with which you do business. Clicking through a Fandango link for a $10 coupon from Reservation Rewards, for example, authorizes the company to obtain your billing information from the movie tickets site. (The post-free trial cost: $10 a month.)

It always pays to read the fine print, but there are other warning signs that you've opted in for more than you wanted. Watch out for these three sneaky ways companies entice you to opt in for expensive add-ons and subscriptions:

Travel vendors are particularly notorious for automatic opt-ins, says Ed Perkins, a contributing editor for travel site SmarterTravel.com. Buy a ticket through Spirit Airlines, for example, and you'll find two extras added to your bill: Membership to the airline's Fare Club ($9 for a three-month trial), and basic travel insurance ($12 and up, depending on your fare). "An awful lot of products these sites sell are fully or heavily nonrefundable," says Perkins. "They're hoping there will be less of a hassle with consumers if you have travel insurance." Wanted or not.

Solution: Companies prefill options to suit their needs, not yours, says Sherry. Before you click to confirm a purchase, go through each additional offer to ensure the only boxes checked are the ones you selected yourself.

Solution: Be wary of freebies that pop up after a purchase, or are connected in any way to a company that may already have your credit card information. "You're not getting something for nothing," says Dworsky.

Blame your mother for warning you not to sit too close to the set, jokes Michael Gartenberg, research director for Jupiter Research. Masking the problem further, these charges show up on your cellphone bill rather than your monthly credit-card statement, he says. They're harder to spot there amid the mass of cellphone fees already tacked on to your basic plan.

Solution: Because third-party companies bill you indirectly by tacking charges onto your cellphone bill, the Mobile Marketing Association requires them to use a double-opt-in system — i.e., you must request the service and then confirm your interest. That's a red alert you've bargained for more than a one-time purchase. Ringtones.com, for example, requires online entry of a PIN texted to your phone to download a ringtone, while most cellphone providers request confirmation before permitting a text message to celebrity gossip show "The Insider" (which incurs a 49-cent premium content charge).

If you don't confirm, or actively decline, you won't be charged. Just don't expect to get whatever cellphone bling lured you to the site in the first place.