No ones forced to even look under the cap. The concept works on buying the drink, not buying a song. If you just wanted the song this would be pointless since the songs are 99 cents and the drink is generally over a dollar, and 1 outta 3 to win is 99 cents vs 3 bucks per song, bad ratio to me. It's not like they bought the song and then had to download iTunes. They bought the drink not the song, and if they choose to, get to download it at their will if they care to, have the time, the patience, or just remember to not throw away or misplace that little cap.
With your example and what is going on here it's more like getting a lottery ticket BECAUSE you purchased 20 dollars or more worth of gas, not buying the ticket/song outright, then having to go to xyz's site and install themexp or whatnot.
You neither buy the song nor the ticket, you buy the gas or the pepsi, and as a bonus you can mess with the extra stuff if you want, but at no time is it forced, it's just an extra option available and you have to follow whatever guidlines or rules there are if you want to claim your "winnings."
Doesn't seem like a big deal to me I guess, it's not like apple isn't a trusted company, or is wanting you to download some harmful proggy or putting spyware in it. And it's not like a ton of people don't already have and use this one, not to mention it's not just PC people getting this stuff, and every mac comes with iTunes installed.
I can see not liking it, but I can't see how anyone feels like this is some kind of grand evil scandal.
Its real easy to understand I'd think, Apple has a program for playing, burning, and ripping music, it also has a music store built into it. They decide one day to do a contest to allow free music downloads and voila, here it is. They're not saying to download music from our site you must also install our program. THERE IS NO SITE AND NEVER HAS BEEN. Since iTunes came out the only way to access the store has always been through the program, and it should come as no surprise that it is still this way since this exact same contest ran a few months back and worked no differently than it does now.
No one is being denied access to download from itunes or apples site, it doesn't exist, never has, probably never will. iTunes works exactly as it always has, and that means downloading music through the proggy like it was designed, because the store itself is a part of the program period, take it or leave it I say.