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.
1 They also require a monthly data plan. 2  The 16GB Wi-Fi plus 3G iPad costs $629. 3  The Wi-Fi plus 3G iPad with 32GB of flash drive memory costs $729. 4  The Wi-Fi plus 3G iPad with 64GB of memory costs $829. Ear buds cost about $5, and noise-canceling headphones cost $20 to $500. 2  Purchasing additional music from the iTunes Store costs about $1 per song. 3  See: How Much Does an MP3 Cost.