Wsrtjtyk

I have a site with bunch of radio channels. User comes to the page and listens to the radio. GA's session expires in 30 minutes. What better way to show GA that user is still on the page within a few hours or days ? Can I use gtag events for that purpose ?
Like this

gtag('event', 'aaa', {

  'event_category' : 'bbb',

  'event_label' : 'ccc'

});

The easiest way would be to set a longer session duration in the property settings. You can change this to up to four hours (basically exactly because of your usecase, podcast and video sites often require users to stay inactive for more than thirty minutes).

But as you figured out you can also send and event in regular intervals to keep a session alive. The non-interaction flag must be set to false, but that's the default in any case. Don't overdo it, because a session will also end after 500 hits.

The added benefit of events if that it should get you more precise measurements for things like session length. Since session length is calculated as the delta between first interaction time and last interaction time the last page in a session is often not properly counted, since users who leave do not have any more interactions. An automatic event will provide a more accurate second point of measurement.

Disadvantage is that auto events will break your bounce rate (since even users who call your page and then do nothing will be counted as active after the first auto-event). So maybe you can tie this to some action in your page instead (i.e. maybe your media player can send an event every few minutes while it's running).