According to @lizgannes ...

An iPhone app that is consistently in the top 10 of the U.S. popular app charts gets 1.5 to 2 million downloads per month, according to Oliver Lo of App Annie.

Meanwhile, Peter Farago of mobile analytics provider Flurry told me, “What makes a hit, in our view, is 1 million daily active users per platform (e.g., 1 million on iOS and 1 million on Android).”

Jack Abraham, who founded Milo and now leads local at eBay, was one of the earliest investors in Pinterest a few years ago. What got him to notice that company when so many other people couldn’t tell it was about to become a juggernaut? It was the growth chart, he recently told me.

“What I look for is 1 to 3 percent sustained growth in users per day,” Abraham said. “It could be as small as 5,000 or 10,000 users if it has that growth.”

The CEO of Mixpanel Suhail Doshi says to pay attention to retention numbers: 20-30 percent is good; 50-60 percent is great.