Complex sentence: Revenue from this business was brisk until the late 1960s, at which time trading stamps began to lose popularity and the company was renamed "Carlson Companies" in 1973 as it diversified into various hospitality and travel industries.
Split into simpler sentences: Revenue from this business was brisk until the late 1960s, when trading stamps began to lose popularity. The company was renamed "Carlson Companies" in 1973 as it diversified into hospitality and travel industries.