Q: Where do I buy dollar for dollar gift certificate online to redeem instantly?

Hey TeeSpin,

Thanks for the question, and welcome to Apple Support Communities.

It sounds like iTunes Gifts are for you. Here is a rundown of how it works:

iTunes Gifts

 

It’s easier than ever to send an iTunes Gift for holidays, birthdays, or any occasion. Because now you can buy them on the iTunes Store from your iOS device or computer.* And in any whole-dollar amount between $10 and $100. Choose a theme and add a personal message. Then have your gift emailed on the spot, or pick a time for it to be delivered. Your recipient can redeem the gift for exactly what they want — songs, movies, TV shows, apps, games, books, and more.

For more information, see the following:

Apple - iTunes - Give the gift of music and more.

http://www.apple.com/itunes/gifts/

iTunes: Sending iTunes Gifts

http://support.apple.com/kb/HT2736

Thanks,

Matt M.