Facebook Chief Operating Officer Sheryl Sandberg said during the social network’s second-quarter earnings call last week that revenue from mobile application install ads continued to grow, and Product Manager Deborah Liu elaborated on that in an interview with Fast Company.

Liu told Fast Company some 8,400 developers purchased mobile app install ads during the second quarter of 2013, more than double the approximately 3,800 that did so during the first quarter.

Those ads drove 46 million app downloads in the second quarter, compared with 25 million in the previous period, Liu told Fast Company, adding:

Developers come to us and say, “This is exactly what we were looking for.” This is the kind of thing that all startups and all companies need. App discovery is such a big problem.

We’re showing fewer apps to people and giving better recommendations to people over time. And obviously, the fewer impressions we’re using for a specific app install, the better the whole system works, and the prices actually go down.

Mobile app advertising outfit Fiksu told Fast Company mobile app install ads have helped it lower its costs for acquiring new users by 15 percent to 60 percent.

Readers: Have mobile app install ads ever prodded you to download and install apps?