Erika Nardini, AOL's marketing chief for its advertising division, is leaving the company at the end of the year. She will be succeeded by Allie Kline, CMO of AOL's ad-tech division. She will add Nardini's duties to her current responsibilities. Kline and Nardini both joined AOL in January last year, but since then the company's advertising technology and premium advertising businesses have begun to converge. In the third quarter of 2014, AOL's overall advertising revenue rose by 18%. AOL's ad-tech division contributed the largest piece of that revenue.