4:05 PM -- Maybe we should call it The Instagram Effect.

Big money venture capital spending on mobile companies is right in the spotlight following Facebook 's $1 billion bid for the mobile photo sharing app.

Mobile photo sharing app developer Path has grabbed a $30 million round, while Wi-Fi video play Quantenna Communications Inc. just raised $79 million. (See Video-Over-Wi-Fi Startup Bags $79M More .)

When trying to glean what mobile social apps might get bought next, however, I think there's a simple rule-of-thumb you should look for with a hot property. If it's going to be a big social app, then your friends and the people you meet should be talking about it, not just the marketing people or the founders!

For instance, several friends have told me separately how much they're using free messaging service, WhatsApp Inc. That's not the sort of buzz you get on an app every day.

Seems to me that you can't just fling money around and expect a return in this wireless bubble: If you're looking for mobile social success, you have to go where the buzz is.

— Dan Jones, Site Editor, Light Reading Mobile