[greatzebu]

It never attracted a giant user base. I miss Reader (especially the pre-G+ integration version) and I wish it was still around, but it's not mysterious why it got killed. If it had hundreds of millions of users it wouldn't have died.

[tomkarlo]

This: Google's scale of operation doesn't work well for a free service with a small number of users - the legal, localization and support overhead is disproportionately expensive on a very small service, unless it's a paid one.