Why colleagues ignore the calendar ping
Nobody opens an internal invite thinking it is unimportant; they open it, see no reason, and defer the decision to a later self who never arrives. The forward-only culture finishes the job โ an acceptance means nothing when the person who accepted forwarded it to an assistant. An internal webinar has the same attendance problem as a public one and a worse one on top: the pressure of politeness, where everyone says yes on the shared calendar and no one appears.
The fix is not a louder ping. It is an invitation that states a reason, asks for a decision worth making, and puts the answer somewhere real. A webinar page does exactly that: colleagues register with their names, the list updates as replies come in, and before the session you open it and know โ by name โ who is actually coming. A registered list is not attendance, but it is the first honest draft of it.