In the 1970s, CES was still largely a trade show, with little mainstream media coverage. The first CES of the decade brought the commercial debut of the Videocassette Recorder, which was first marketed as an easy way to record TV shows for later viewing.
VCRs had been around since the mid-1950s, but they cost around $50,000 and were used mainly by TV networks.
An awestruck audience at the 1970 CES loved the VCR's convenience -- but Hollywood battled back, warning that piracy would run rampant and kill network television.
The VHS remained on top until the late 1990s, when the DVD (unveiled at the 1996 CES) began to take over. By the early 2000s, the DVD was king of pre-recorded releases. But even today, blank VHS tapes are a major medium for recording content -- and VCRs are still big sellers, though they're now most often found in DVD player combo units.