The best reaction I got was an in-house demo to a group of LAMP stack developers. These guys glaze over at the mention of MongoDB, so I decided to start with the demo and use MySQL (numtel:mysql package).
At the time we were testing MySQL migration plans and had a MySQL server in one datacentre slaving off another in the same datacentre, slaving off another in a different datacentre.
Server 1 had a remote phpMyAdmin, and server 3 had my Meteor dev server connected via numtel:mysql with a browser to render the output:
+-----+ +-----+ +-----+
|MySQL| |MySQL| |MySQL|
| (1) |-->| (2) |-->| (3) |
+-----+ +-----+ +-----+
^ ^
| |
| +------+
| |Meteor|
| |server|
| +------+
| ^
browser |
(phpMyAdmin) browser
Those of you who have used the numtel:mysql package will know that it connects as another MySQL slave in order to get the replication log data. So, essentially I had four MySQL servers in a line.
I then used phpMyAdmin to alter the timestamp on a row in server 1. The change propagated across two datacentres and the Internet (to my laptop), and Meteor rendered the change before phpMyAdmin had refreshed its page. Jaws dropped. When I was asked to see how it was done (23 lines of JS) I knew they were hooked. 