Three years ago, Esri published the blog post Using Google Docs in your ArcGIS Online maps. However, Google has since dropped support for CSV in the spreadsheets, meaning they can no longer be published as a CSV. Here is the work-around for this problem.
When you publish the sheet, you'll end up with a URL like this:
https://docs.google.com/spreadsheets/d/<KEY>/pubhtml?gid=197606809&single=true
Change that URL to this:
https://docs.google.com/spreadsheets/d/<KEY>/export?format=csv&id
