Modern technology is used by broadcasters to maximize revenue from advertisements by auctioning the advertisement slots in real time. Live channels have opportunities to maximize revenues from advertisements when there are lots of eyeballs which suddenly increase the viewership of the channel. Unfolding of events of very high interest to viewers – like a big game getting into a very close finish on a sports channel, or some very important breaking news on a news channel.
The broadcast content is digital with clearly marked digital demarcation (slots) tags for advertisements. Regulators may allow a certain time duration say few minutes of advertisements for every half hour of broadcasts. These slots are like a production inventory and are used to maximize revenue by booking a part of these slots in the beginning and leaving some parts for last minute inserts based on the viewership ratings during live broadcast. There are further opportunities of creating additional time slots by software which time slices (compresses or skips) the live broadcast. An odd frame or a few seconds of feed is removed such that the break in continuity may not even be noticed during viewing.
The advertisements are put in a separate queue and the software also manages the queue to insert them dynamically into the live broadcast feeds so that viewers see a continuum of live feed and advertisements mixed by software cleverly without any apparent breaks.
To maximize revenue, the broadcasters use the inventory of advertisements slots very much like an airline would optimize their revenue by selling the first seats on a plane at standard costs and as seats gets full the price of the last few seats become more expensive or less based on last minute demand.
Software is also used to compress the advertisements into different time durations such that one can get the same key message from the advertisement even though it played for different duration. As an example one sees many a time that same advertisement play for 30 seconds or 15 seconds but gives the same message with very good dynamic edits of the same. This technique is also used to sell the advertisements at fixed price and vary the time slot such that during peak viewership the advertisement could still be inserted for a smaller duration.
All these clever programming is used to mix and match the live broadcast with dynamic advertisement inserts to maximize revenue.