Building free-to-play titles with the intent of engaging core gamers is vital because they're more likely to spend money, and the few who do spend a significant amount — an average of $60 per month, Kongregate CEO Jim Greer told Develop.
"For a developer, core gamers are just engaged, and in any field it's the most engaged people who are most willing to pay money," said Greer.
According to Greer, only about 2 to 3 percent of users ever spend any money in a free-to-play Kongregate game on the web — a figure similar to other free-to-play titles, although Greer said the percentage is "less than a quarter of that" for a standard Facebook game that isn't geared toward core gamers.
"But the average amount spent per month by a player who does spend is about as high as it gets, $60 a month since January," said Greer. It's unclear if he was talking about the one month since January 2013, or the 13 since January 2012. That small group of high-paying customers — often referred to in the industry as "whales" — is what keeps most free-to-play games alive.