I bought a publishdrive lifetime membership from appsumo mainly to reach the Chinese and European markets not already offered in Smashwords, Draft2Digital, and StreetLib. The platform took a little bit of getting used to at first as it is not as easy to use as Draft2Digital. I used Calibre to edit my epubs and uploaded them to publishdrive. Publishdrive would error check, send a notification email, and I'd go back and fix the errors in Calibre. Ultimately, I've used them to distribute over a dozen books. The only glitch that keeps happening is that sometimes the dropdown menu for choosing BISAC codes stops working, and I have to save a book as a draft and come back in a different browser.