Hello, I'm new on this forum, and I would need your experience and knowledge of ipods to help me to make some estimation. Basically, I have a market size project to do for my school and some information are missing : - What is the percentage of users buying ONE earbud or a headphone per device (iphone, ipod, ipod touch) in addition to the one coming with the initial purchase? 2? 3? - same question par age category (<17 ; 18-24 ; 25-34 ; 35-44 ; 45-54 ; > 55) - Which percentage of iphone owners also have an ipod? What is this percentage for teenagers (12-18 years old)? - What is the percentage of the teenagers buying an earbud or a headphone ONLY to listen to music (eg an earbud not including call functions)? - What is the percentage of utilization between earbuds and headphone? I would be interested in collecting your opinion about that ! I thank you so much in advance for that ! Another idea I have to find these numbers is to go and speak with vendors (best buy, music shop,...). Any other ideas are welcome. Finally if anyone has some tips to find apple products sales forecast, and market information about third-party accessories, it would be great as well ! I thank you so much in advance for the help you would provide me.