When Rousseau wrote his social theory, concepts of liberty and freedom were not new ideas. Hints of social contract reasoning are found in earlier works, most notably in Book 2 of Plato's dialog The Republic, as well as, in Socrates.
The total spending per iTunes account is $43 per year across all media, says Dediu. At 575 million iTunes accounts, that works out to $24.7 billion of consumer spending at iTunes per year. The average iTunes account's annual spending on software has followed music's trend, falling to $9 from $42 in 2008. However, average annual spending on apps has gone in the opposite direction, rising to $16 this year from $7 in 2008.
Editors' Note: You must be 17 years old to download this application. The download button opens the iTunes App Store, where you may continue the download process. You must have iTunes installed with an active iTunes account in order to download and install the software.