Just had a quick scan of the Kindle edition and it looks like a good general intro: The Ultimate Guide to #eCommerce https://zapier.com/blog/ecommerce-book/?utm_campaign=The%20Ultimate%20Guide%20to%20eCommerce%20Software%3A%20A%20New%20Free%20eBook%20From%20Zapier&utm_medium=email&utm_source=blogblogposts
Source
https://twitter.com/danielmcclure/status/819275265779986432
https://twitter.com/danielmcclure/status/819275265779986432