Thanks for the suggestion!

Maybe you can list here these use cases that you think this feature will allow ?

We need to know the use cases and problem trying to solve, then we can think of best way to solve them. Cheers!

One could call this "virality-alert", too.
If PIWIK would offer to send an automated alert on overall traffic / certain pages traffic going thru the roof on short notice, that would be an awesome tool.
In times of FB & co, one may have to deal with extreme peaks in traffic due to some viral article and might need to take action really quickly, thats why the "watchdog" is a great idea.

@mattab

Maybe you can list here these use cases that you think this feature will allow ?

My use case for an alert with shorter time period (1 hour or even 30 min), is to be able to see a sudden drop in traffic, and to take action immediately after that drop.

I run matomo on a standalone machine that track websites on other machines. It would help in case of server down (or partially down) => traffic drop.

I've just installed the alert plugin for that, but I cannot use it as is without a shorter period option.