I wrote that startups crafted in Facebook's image often produce next to nothing, but I think the same statement is actually also valid when applied to Facebook, now that you mention it. Attracting people's attention (as evidenced by traffic) is not the same as producing a valuable product, no matter the company. If Facebook did actually produce something of value, it probably would not have had any trouble extracting money from the site in the first place. As it so happens, the lack of an obvious, sustainable business model was the reason I decided to work on other things, instead.