Another great channel where you can distribute and publicize the theme is the Magento Connect website. This site is the place where you can find free and premium extensions and themes for Magento. The sales will not be through this website, but you have to share the link to the theme page of ThemeForest.
The following screenshot shows what the Magento Connect website looks like (http://www.magentocommerce.com/magento-connect/):
Register an account and then you will have the option to upload your extension with all the details using a form similar to the one used by ThemeForest. The item must be approved by the team, and only then can it be found on the website. The approvals take about 48 hours and the price is the cost of the extension that you can find in your theme page. You can also consider selling the theme without going through a marketplace such as ThemeForest; in this case, you can set your own price in Magento Connect.
Source: Sacca Andrea (2014), Mastering Magento theme design, Packt Publishing; Illustrated edition.