That's 3.6 million Facebook users in the Breakup Notifier database, not 3.6 million users of Breakup Notifier.

Since the app pulls in all your Facebook friends, and people generally have a few hundred friends, I suspect the number of users of Breakup Notifier is in the tens of thousands.

It's a lot higher than 10,000 [1].

[1] - Dan told me.

EDIT: (the parent comment once said 10,000, now changed.)

Though people don't usually have unique friend sets--if a group of 10 people all know eachother and are friends on Facebook that's just 10 users.

Yep, I'm kicking myself. And to think I was just about to implement Facebook Credits. Fool me once...

As appealing as 3.6M users sounds, "reach" apps like this often make really bad money. He would've made no more than $500 if he was doing well. He was capturing emails, so that had long term potential, but he wouldn't have become rich from three days of FB user impressions.

it was only a weekend project, only running for a few days before takedown - under those circumstances I'd call $500 a solid outcome, especially when the alternative is $0.

As someone with little experience with monetization, which ad networks do you usually use on a site with - at the time - no traction? Yoggrt, Fusion Ads and Deck Network come to mind, but you can't use nor apply for them, so what does that leave you?

Sites like The Deck aren't really ad networks, they're more like vanity projects for hipster web designers. AdSense would not work well either with no text content.

However CPM banners like Doubleclick combined with affiliate links to dating sites could do very well indeed.

Do you have any article or vendour links I could take a look at? I've struggled to find good banner ads.

AdSense or affiliate ads (i.e., Match.com). No one said it was pretty.