Amazon is now selling so many different subscription services that a consumer signing up for every single one would spend $839 a year. And that means subscriptions are an increasingly important part of Amazon’s revenue. The flagship $99-a-year Prime subscription alone could generate up to 7% of Amazon’s U.S. e-commerce revenue, estimates suggest.

While Prime is the best known of Amazon’s subscriptions—highlighted by Tuesday’s Prime Day sale to drive more membership—Amazon sells at least seven other offerings. Some, like the $5.99-per-month comics subscription offered by Amazon subsidiary ComixOlogy, are niche products. Others, like Amazon’s $59.99-a-year Dropbox competitor or its $24.99-a-year service to store your personal music files on Amazon and stream them to any device, remain relatively obscure because Amazon doesn’t advertise them heavily.