Heinecke had his first hotel venture in 1978, the Royal Garden Resort in Pattaya. His business ventures have included advertising agencies and other hotels in Bangkok, Hua Hin, Phuket, Chiang Mai, Chiang Rai as well as outside of Thailand. He also introduced American-style fast foods to Thailand in the late 1970s and 1980s – brands like Mister Donut, The Pizza Company and Burger King. Heinecke naturalized as a Thai citizen in 1991, renouncing United States citizenship in the process. He was the president of the American Chamber of Commerce in Thailand and sat on the Prime Minister’s Foreign Investment Advisory Council. He is a supporter of the Thai Elephant Conservation Centre, and authored "The Entrepreneur", which has been translated into a number of languages.