Feedly survives the outages from the post-Google Reader rush, adding users, feeds and maybe revenue

Feedly, which has emerged as one of the best replacements for Google (s goog) Reader in the wake of the announcement that Google will abandon the RSS service, has been taking on millions of new users and at the same time steadily pushing out new features. But the growth in users hasn’t been completely uneventful.

Feedly Co-founder Cyril Moutran

Feedly Co-founder Cyril Moutran

In the five weeks since Google said it would shutter Reader later this year, the Feedly site has gone down two times, co-founder Cyril Moutran told me in an interview this week. The first time came right when the Google Reader announcement was made. There was a “huge load on our server,” Moutran said. “It just came, slammed us really, really fast. … What broke for us was really bandwidth. Basically, just having so many users coming in, the bandwidth was just everybody was coming in, and the servers were not responding.”

So engineers moved static content off the Feedly servers inside a data center and, somewhat ironically, onto Google App Engine, which scales very nicely, Moutran said. Dynamic content stayed put on the Feedly servers, which store terabytes of data, including indexed content from the feeds users subscribe to.

Less than a week later, Moutran said, “we saw another really, really crazy spike.” The site went down again. Developers took a look at the code that communicates between the client and Feedly servers, and tried to make the client more efficient, thereby reducing the load hitting the servers. “Then we had to order some more hardware,” Moutran said — load balancers, to be specific.

That second outage came on a Monday. As it turned out, Feedly gets more traffic on Monday than on any other day, and generally speaking traffic is higher on weekdays than on weekends. Desktop traffic picks up at around 8 a.m. local time and decreases around 6 p.m. Why? Many Feedly users look to the service “not so much in a casual context but more to catch up with what’s going on with the industry,” Moutran said. People use Feedly for work, in other words. Lawyers, designers, and writers are typical business users.

As many more users get on board — more than 3 million had joined since the Google announcement as of April 2, on top of 4 million users active before the announcement — more feeds pile up. The number of feeds is now up to 100 million, Moutran said.

With many more business users and a greater variety of content, monetization is a bigger question, and Feedly feels it must accelerate its efforts in that direction. The company, which is based in Palo Alto, Calif., and has 10 employees, is now looking at how it will introduce a premium or pro version later this year. Feedly could also add a way to take revenue by providing streams of publishers’ premium content inside the desktop and mobile versions of the application.

While plenty of people find Twitter handy for getting news, the migration of millions to Feedly shows the desire for a strong RSS reader still exists. If that desire keeps steady and if Feedly can keep adding features that interest users, it could turn Google’s trash into Feedly’s treasure.