Free credit reporting company Credit Karma reported more than $500 million in revenue in 2016 — a 50% increase compared to the prior year — hitting 70 million members since the launch of its flagship product — credit monitoring — in 2012, the company announced this week. What’s the secret to its success?

Free products that customers love, CEO Kenneth Lin said during the Future of Fintech conference this week.

In addition to record revenue and members — which are in line with the company’s estimation of adding 1 million to 2 million users a month — Credit Karma also had 1 million tax returns filed through its system during the inaugural season.

The company, which recently launched its mortgage refinance and unclaimed money (a site where consumers can check if they have any unclaimed money laying around) products, is now focused on expanding its free tax prep service “soon,” as well as adding new products to the lineup, a spokesman told Bank Innovation.

However, “just like all the other products on Credit Karma, our tax offering is and always will be completely free — no upsells or hidden fees,” the spokesman said about the future expansion of the tax prep.

Credit Karma uses machine learning and AI to run “nearly two billion” prediction models daily, allowing the company to recommend financial products – such as credit cards – to customers. The fintech makes the main chunk of its revenue from generating leads to clients such as Capital One Financial Corp., Barclaycard, JPMorgan Chase & Co., and Citigroup, among others. Credit Karma itself is staying clear from lending: “We have no plans to become a lender – our ability to remain neutral when recommending the best loans for our members is critical,” the spokesman said.