Let’s walk through these branching possibilities for what this advertising buy could mean.

We don’t know much about how Facebook conducted its investigation. We do know that they repeatedly denied there was Russian influence during the election, and then copped to it in early September.

A Washington Post article fleshed out a few details, including that President Obama personally spoke with Mark Zuckerberg after the election to get him to take the misinformation campaign seriously.

The problem appears to have been that Facebook’s spam- and fraud-tuned machine-learning systems could not see any differences between the “legitimate” speech of Americans discussing the election and the work of Russian operatives.

Here’s the description of the process that eventually found the ad purchases:

Instead of searching through impossibly large batches of data, Facebook decided to focus on a subset of political ads. Technicians then searched for “indicators” that would link those ads to Russia. To narrow down the search further, Facebook zeroed in on a Russian entity known as the Internet Research Agency, which had been publicly identified as a troll farm. “They worked backward,” a U.S. official said of the process at Facebook.

I take this to mean that they identified known Internet Research Agency trolls, looked at the ads they posted, and then looked for similar ads being run, liked, or shared by other accounts.

Why this would have taken several months is unclear. Journalist Adrian Chen was able to build out a network of Russian operative–run pages without any of the data that Facebook has. Given that the story he wrote ran in The New York Times Magazine in 2015, you’d think that particular agency would have been the first place Facebook would have looked.

That could be one reason a Congressional investigator told the Washington Post that Facebook had only hit “the tip of the iceberg.”

But that’s only one possibility. The ads could have done exactly what the Russians intended, even at this limited scale, as part of a broader information campaign.

Some context: Facebook ads can do several different things. They can promote a piece of existing content somewhere on the internet. They can be used to try to drive “likes” to a page. They can be used to get people to watch a video.

With the right (salacious/truthy/fake) material, even a little money can go a long way. The Daily Beast had a Facebook ad specialist calculate how far $100,000 worth of Facebook spending would go and came up with a range of 23-70 million people, depending on how they were targeted.

Vice News talked with the owner of a right-wing Facebook page who uses Facebook ads to juice conservative content. After spending $34,100, the man controlled pages with 1.8 million likes. With that distribution base, he was able to push out content that could, on occasion, do serious numbers. “With a few advertising dollars, one April video ... received more than 27 million views and over 450,000 shares, spreading so pervasively into the conservative media universe that Donald Trump’s official Facebook page shared it two days later,” Vice wrote.