I really love that you can buy individual karaoke songs these days, rather than an entire CD+G disc. This is really great when you are looking for specific songs that either aren’t on any CD+G discs you’ve found or are only available on compilation discs. The problem with many compilation discs is that many of them have the same popular songs on them. I’ve got several discs with “I’ve Had the Time of My Life” on it now. Buying individual tracks makes the money you spend on karaoke songs more worthwhile. Also, some of the digital karaoke stores will make custom CD+G discs for you, letting you pick all the songs that will be on it. This option is perfect for those with a karaoke machine that plays CD+G discs but not MP3-G files.
Amazon is not in this list currently. While I have found many digital music downloads there that say they are karaoke tracks, they are audio only, and do not include the lyrics onscreen. I logged a ticket with Amazon support in February 2015 to confirm whether they sold any MP3-G tracks and was told that they do not yet. The agent did say they would submit the idea to the powers that be, so if enough people show interest, I am sure Amazon will offer them at some point.