Move important side effects from do() to subscribe()

Also, I have had the case where I wanted a required side effect to occur but only when there was a subscriber for the "main" observable. I suppose the "correct" way to enforce that would be to expose an observable that is the result of merge ?

Julia, I do think you are right about triggering twice regarding click observable. It would be one hit as click is hot observable.

what about the situations when we use the async pipe in Angular? the subscription and unsubscription happens automatically in the template, so we can't have subscribe