How to Create an iMix in iTunes
The iTunes Store offers the iMix section for sharing your playlists with other iTunes users. Although you can submit a playlist of any items to be published in the iMix section of the store, only items available from the store are actually published. Unavailable items are skipped.
Select the playlist in the Playlists section of the iTunes Source pane, and choose File→Create an iMix.
iTunes displays a warning dialog before accessing the iTunes Store to publish your playlist.
Click the Create button in the warning dialog.
iTunes displays the iTunes Store sign-in dialog.
Enter your ID and password and then click Publish.
iTunes selects the iTunes Store option in the Source pane and displays the iMix page. You see the iMix playlist that will be published, which includes only available items from the store.
Edit the title and description for the iMix playlist and then click the Publish button.
iTunes publishes the playlist in the iMix section of the store. Others can browse the playlist and buy any items.