Join Mileage Plus if you have not already done so. Point your browser to the link listed under Resources or call Mileage Plus customer service at 1-800-421-4655. No matter whether you join online or over the phone, you'll need to have your full name, street address, phone number and email address on hand. Additionally, you'll need to create an online password and designate a security question to protect your account. If you register online, check the box next to "Send me timely email offers from United" or tell the representative on the phone you'd like to receive them if you sign up that way---this is essential, as United sends out its e-certificate offers via email.
Make a qualifying purchase or engage in otherwise qualifying activity to obtain your e-certificate. As an example, United offered 10-percent-off e-certificate good for use on any United Airlines flights to Mileage Plus members who registered prior to March 31, 2010, and used their Visa cards to purchase a round-trip ticket between February 1 and March 31, 2010.
Call Mileage Plus customer service at 1-800-421-4655 and ask the representative if there are any promotions you might not have heard about via email. As a result of spam filters and the general volume of email users tend to receive these days, it's possible you might have missed it.
