Steve Jobs unveils the first iPhone on January 9, 2007. - 

It's quiz time on Marketplace Tech. 4 million songs. 82,857 address books. $1,999. $14,000 per square foot: Can you guess what these numbers mean?

This week, Ben faces off with Sam Biddle, editor of Gawker's tech news and gossip website, ValleyWag. Click on the audio player above to play along.

Follow Ben Johnson at @@TheBrockJohnson