A friend has a theory that if an ad say "X is Y", it's because a bunch of surveys and marketing studies have shown that people think that X is ~Y. So if people think some soft drink is unhealthy, the ad companies will make ads showing it is healthy. He takes it a step further and says that all ads are lies. I wouldn't go that far myself, but I think that it's not just Facebook and it's not just election lies that are being spread.
The $1mil number in itself doesn't seem too impactful, but when you take it into consideration with other reported findings, such as $55mil spent in the last year to influence the general public during election season, or the $5mil spent to honey pot activated and enthusiastic partisans -- it starts to add up -- and I imagine the numbers are much bigger, especially when you consider legitimately funded misinformation from Super PACs and the like.
The Citizens United decision and resulting Super PACs are one of the worst things to happen to US democracy. Money is not speech. Free flow of untraceable money into our elections means that political ads cost more for the direct candidates because of competition. There's only so many hours in the day so if someone can buy ads for 95% of the reserved ad time, by necessity all other speech is reduced. I think we need a constitutional amendment to address it.