Push update what is it? It is a mechanism that GetProperties supports so that the Server can push a value to a client mashup. This will allow you to see values update in your mashup real time without needing the refresh widget.
Another great way to use the push updates is to propagate events that tie to specific content fetches.
Let's say your mashup has three areas: KPIs, Alerts, Live values.
Using some logic server side you can set up a 'tracker' Thing with properties that indicate that one of those areas has updated data.
Bring these notifications as property values into the mashup using GetProperties and as the Server pushes updates to the mashup runtime, you can map it to a Validator or Expression widget (set to autoevaluate) which in turn can now run the necessary Service to fetch the updated information for the specific area.
