When you purchase a full price ticket to Blue Man Group, use promo code "SKYDECK" to get a free* ticket to, you guessed it, Skydeck Chicago.
*Restrictions apply. Not available in conjunction with any other offer.
***Blue Man Group ticket and Skydeck voucher must be picked up at the Briar Street Theatre box office. If you order through Ticketmaster weeks in advance, your ticket and tower voucher can be mailed for an additional fee.