1. **Libro.fm**: This service partners with independent bookstores to offer a wide selection of audiobooks. When you purchase an audiobook, a portion of the proceeds goes to a local bookstore of your choice.

2. **Kobo Audiobooks**: Kobo offers a subscription service similar to Audible, as well as the option to purchase audiobooks individually. They have a wide selection and often offer promotions and discounts.

3. **Google Play Books**: Google Play offers a variety of audiobooks for purchase without a subscription. You can listen to them on any device with the Google Play Books app.

4. **Apple Books**: Apple Books offers audiobooks for purchase directly through their platform, which can be accessed on Apple devices.

5. **Scribd**: Scribd is a subscription service that provides access to a large library of audiobooks, as well as eBooks, magazines, and more.

6. **Chirp**: Chirp offers limited-time deals on audiobooks without a subscription model. You purchase audiobooks individually, often at discounted prices.

7. **OverDrive/Libby**: Many public libraries use OverDrive or its app, Libby, to lend audiobooks to library members for free. Check if your local library offers this service.