As another data point, I've seen the exact same thing. About 8 years back, I worked at a funded startup that got tons of press, because we were all teenagers and it was the height of the dot-com boom. We got a spike everytime we were mentioned, but it didn't stick, and we were actually losing regular users (they thought we'd gone all corporate, which I guess we had).

Build something worth talking about before you get people talking. In our case, we got press because of who we were and not what we'd built, and that's not sustainable.