Widgetmaker: Lost developer enthusiam cuts Facebook's value by $10 billion

Earlier today, we reported that participation in Facebook's developer forum is down, most likely due to Facebook's new restrictions on Facebook-application spam. We praised these new rules, saying Facebook won't miss its lousiest apps. Now an executive from a major, well-funded widgetmaker tells us, "Your post misses the point." Before you reach for the "Block" button, hear him out:

FB's valuation is driven by the perception it can serve as a platform (or launching pad) for derivative businesses. Without that perception, FB is a $3-5 B company. Period. When developers lose enthusiasm for the "platform," every FB employee has their net worth cut by 67%.