Scribd Counts 50 Million Readers
mediabistro.com
mediabistro.com
What else should be noted is that only 1/5 of their traffic is US-based (source: Quantcast Directly Measured Data). Sometimes having 50 million readers is only a great thing when they are from areas that are [easily] monetizable. Not sure what (US) company will want to spend money advertising to a guy in Singapore who is learning how to bake a cake.
If only bandwidth was free.