Facebook's user growth has stalled, or gone in reverse, in its most profitable markets (FB)

Facebook is stalling — or going in reverse — in two of its most profitable markets. On Wednesday, the Californian social networking company announced its Q2 financial results. They failed to meet Wall Street's expectations for revenue, daily active users, and monthly active users, and the stock dropped as much as 10% in after-hours trading. In most of the key metrics, the company is still growing, albeit at a slower rate. But one cause for concern is Facebook's daily- and...