Dan Dennis said:Most people couldn't tell you the call letters of a TV station if their lives depended on it. Nobody says, hey, Maude, turn on KPRC. It's always "Channel 2." Or Channel 11. Or Channel 13. Or Channel 39.
Up here in D/FW, the only station that could be identified by its calls is maybe WFAA - and that's only because they're the only "W" TV station in the market (and one of only two in the state, WOAI in San Antonio being the other). So it makes them unique. But even then, most people will call them "Channel 8."
Also in DFW, channel 21 identifies themselves on air as "TXA-21", which is a shortening of their call letters (KTXA). And channel 52 uses their KFWD call letters prominently in their on-air identifcation. But I'm not sure how many viewers around here would identify either station by their calls, despite the promotional efforts to the contrary.
In other markets, there are stations that are highly identifiable by viewers based on their call letters. KING-TV in Seattle comes to mind -- I suspect that most Puget Sound area viewers could identify "KING" every bit as quickly as they would "channel 5". But I also suspect that KING and the few other heritage stations with highly recognizeable call letters are the exceptions that prove the rule -- because you're right that few people could identify the call letters of the stations that they watch. And even fewer would actually care.