How do you think it'll ultimately happen? Will stations go dark one by one? Is there an alternate use for the technology (like the way TV spectrum can be used for mobile)? Will AM implode all at once, forcing companies to find spots on the FM band?
The content will first move to FM. In many cases, this happened years ago as lots of news/talk and sports stations now have simulcasts on FM, at least translators if not full-power. Slowly, licensees will realize that it is not smart business to keep up a 50kW AM transmitter site for a few hundred listeners listeners, and they will either sell, donate, or turn in licenses.
We've already seen this happen in some markets, including large markets.
- The top-rated Nashville AM is 19th in 6+, a market where no AM station earns above a 1.0 share. There are HD2/translator combos that rate higher than WLAC.
- In Atlanta, WSB-AM is listed #1, but it has a total line reporting with FM simulcast partner WSBB-FM. The next highest rated AM is #19, WCNN-AM, which has a translator and an HD2 simulcast.
- In Dallas/Fort Worth, the two highest rated AM stations without a full-power FM simulcast are #21 and 21, 6+.
Some exceptions to the rule may occur in markets with several strong AM signals, such as New York. But in many markets with only directional facilities, AM is already effectively dead.