SAN FRANCISCO, Sept. 20, 2022 /PRNewswire/ — Sojern, the leading digital marketing platform built for travel, celebrates 15 years this month. Founded in 2007, Sojern has maintained an unwavering focus on travel from day one. It began by targeting travelers with advertisements on printed airline boarding passes, and evolved to encompass the rise of big data, digital marketing and programmatic advertising across new channels, mobile devices…