Video rental chain that peaked around 9,000 stores in 2004 and was effectively extinct by 2013, famously destroyed by Netflix and its own refusal to kill the late-fee business model that was printing money. The permanent cautionary tale about strategic inflection points (see Andy Grove) — Blockbuster wasn't killed by technology, it was killed by an addiction to a current revenue line that blocked it from cannibalizing itself. Relevant check for any founder clinging to a feature or pricing model that "works today."