Member (Front end) Session Keep Alive

I have a user that might be on a page for a long time (watching a video). Is there an easy Ajax call I can make to stop the member session logging out. 

I'm considering a simple ajax get which just checks something on the member service - will this be enough to keep it alive. I'm off to test this myself but wondered if someone knows the answer already?

Steve


This is a companion discussion topic for the original entry at https://our.umbraco.com/forum/64805-member-front-end-session-keep-alive