Raw data available here: https://github.com/the-markup/citizen-browser-georgia
For example the 2008 Dem primaries with Obama vs Hillary. Obama was sure to win it months before the Dem conference, but I can recall CNN still calling it a race...
All the spending happens well before news channels start reporting ballot counts. Multi-million dollar political campaigns do not rely on the news media to tell them how they should spend their ad budget over a months-long election cycle.
By the time news orgs start reporting actual ballot counts, it's too late to spend any more money. A good chunk of votes have already been cast via mail. Poll stations have either closed or are at best a few hours away from closing.