Stelter Co., a marketing company with a focus on nonprofits, announced March 21 the appointment of two employees to its executive leadership team. Zach Christensen has been promoted to vice president of strategy, innovation and marketing. Nina New has been promoted to vice president of operations and will lead cross-functional teams in the areas of sales operations, IT/data security and project management. Both Christensen and New have been with Stelter for 20 years.