I've used other PR service sites like PR Newswire or PRWeb, which are good, but they're too pricey and I can essentially the same results with PR Underground. Affordability and pragmatism.

PR Underground is easy to use and prepare. Press Releases are priced right for Indie Writers who want to promote ebooks quickly and economically to reach mass distribution websites like Google News, other News Websites and Social Media. Press Releases appear on Google search sites almost immediately. PR Underground Press Release is one of the most economical promotion tools I have used so far to promote my science fiction ebooks on Amazon and Barnes and Noble online stores. Sales increased as soon as the PR was released to the media.