From the rules of their 500 millionth iTunes song promotion:
Eligibility. In order to be eligible, entrants must be 13 years of age or older, and a legal resident of one of the 50 United States, including Washington, D.C., Austria, Belgium, Canada (excluding the Province of Quebec), Denmark, Finland, France, Germany, Greece, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland or the United Kingdom. Entrants must enter the Promotion through the iTunes Music Store accessible in your country of residence. There is one Promotion, and the Rules in your country of residence govern your participation in the Promotion. Entrants under 18 should obtain a parent?s or guardian?s consent before participating. Entries are limited to individual consumers only; commercial enterprises and business entities are not eligible. Directors, officers, employees, contractors and agents of Apple, its subsidiaries, affiliates, resellers, or advertising or promotional agencies and members of their immediate families (defined as children, parents, siblings or spouses) are not eligible to participate in the Promotion. To participate, entrants must: 1) have a computer with iTunes software installed (iTunes software is available for free at: http://www.apple.com/itunes/download/), 2) have Internet access; and 3) submit an Entry.