The Olympics and the 2020 election are saving next year's TV advertising sales

If it weren't for the Olympics and the election next year, TV advertising sales would be down again next year, according to MAGNA, an advertising firm.

Why it matters: Engaged live audiences have become a commodity for advertisers, and they are willing to spend big.

• In total, $10 billion is expected to be spent around the 2020 election cycle. That should help push local TV advertising spend to over $20 billion in the U.S. next year.

Driving the news: NBC Sports has sold $1 billion in national ad sales for Olympics, executives said on a call last week. The company is on track to beat its prior record of $1.2 billion in domestic ad sales during the Rio 2016 games.

• NBC advertising executives noted NBC Olympics’ coverage of Rio in 2016 across all of its television platforms "delivered more than 3x the gross audience of the five major pro championships combined that year – the Super Bowl, NBA Finals, Stanley Cup Final, World Series, and NASCAR Homestead."

Go deeper:

• A look at Tokyo's 2020 Summer Olympics prep, one year out
• World Anti-Doping Agency recommends Olympic ban for Russian athletes