We file our VAT MOSS returns with one specific EU country, who then pays all countries which we collected VAT for (usually almost all of them!) under VAT MOSS. We are reliant on their web form providing the VAT rates that we use.
So, even if a third-party website like Avalara says something in a press release, we can't use it until we see it when we file our following quarterly return: otherwise, there could be a case where we collect a low VAT rate, but can only remit at a higher VAT rate, which could be problematic for us!
Now, in terms of Finland VAT ebook rate and Avalara, we're seeing different information even on Avalara. Specifically, the page that we normally look at shows ebooks as excluded from the lower rate:
"10% Reduced Pharmaceutical products; domestic passenger transport; books (excluding e-books); newspapers and periodicals (sold on subscription); admission to cultural events and amusement parks; TV licence; writers and composers; hotel accommodation; admission to sports events; use of sports facilities; domestic transport"
So, our current understanding is that we unfortunately must charge a non-reduced rate.
Thanks for your enquiry, and for being a Leanpub customer!