The short answer is no, someone with Reader cannot access a workbook published on Server. Reader only works with packaged workbooks (twbx files). The workbooks would need to store 'extracts' of the extracts published on server, and then downloaded for someone with Reader to access. If you've only got 1 server user licence, then only that licensed individual wil be able to do any of the downloading, You really don't want to be going down this route and you're starting to get into a very grey area regarding the Tableau EULA.
Server gives the facility to provide that central repository for all your workbooks and users to access without needing Reader. But you'd need to have Server User licences for every named individual that currently develops via Desktop and everyone who consumes via Reader (in addition to the Tableau Desktop licences you already have).
If your consumers are limited then this may not be the most expensive option, but if there is the potential for rapid expansion then the cost of per user licensing may ramp up considerably quite quickly. It will be worth considering at what point it becomes more cost effective to have a core server licence (unlimited user access) vs per named user licensing.
On a separate note, on server you can set up refresh schedules that can run as often as every 15 mins.
Hope that helps.
Thanks for the quick reply Donna,
So in theory I could (as a single user) put all of my workbooks on the server and use the server to keep the extracts fully refreshed, but then at the end of the day I'd need to download each workbook individually as an extract for anyone else to use them via Reader (EULA issues aside).......correct?
I presume then there's no easy way of automating this step, because Tableau really wants lots of server licenses. Which makes sense as a business model.
I agree with Donna.
Once you purchase Tableau Server it almost removes your need to use Reader.
There are some people who have looked into automating this type of thing - see this thread Re: Automated sharing of twbx files which contains some detail from Tableau itself about the licensing issues.
Great - thanks everyone for your Help