I am the author of Open Your Heart with Singing: Mastering Life through the Love of Song. In this book I tell about many singing experiences I have had in my lifetime. I love to sing at seemingly inconvenient times, but it works. I am able to nurture crying children in grocery stores with my voice. I also have done a lot of public speaking, and the audience loves my voice as well.
On my answering machine one time, I sang "Amazing Grace". People would call just to listen to me sing the song and hang up. It's just one of those remarkable things I do. We all have talent somewhere, mine is in my voice. I've done radio, TV, podcasts and more...
I have had formal vocal training for singing, but not much more than that. I've been working much of my adult life doing phone counseling and consulting. Many adults say they call me just to hear my voice. It has a calming effect they say. I also blend humor and song-like aspects to my voice naturally...and that is from years of "training". Learning to listen and respond appropriately with my voice and words has been the mainstay of lifework. I know I could transfer that level of confidence into any product or service that I'd endorse as well.
I have developed a series of meditation Mp3's that are very popular. Thus, my voice works best for calming and persuading the listener toward whatever it is I am focusing on in the meditation. Could bode well for advertising most anything.