Presumably strangers you mean, people you haven't already exchanged email addresses with? I'm hardly likely to bother to send such a video to an older person who doesn't have email.
My point is that *real friends* accept and understand when we say we prefer not to receive cards (suggesting they give that cost to charity) that they acknowledge such and don't send a card.
We used to get a card addressed to people we didn't know but it was not any of the previous occupiers of that address or the name of anyone local. The writing was all spidery so it was probably someone old and now they have stopped so ... ;-(
We also sometimes get a card from what I believe might be my 'cousins' but I don't know them or them us obviously (they address it to Tim and my first wife's name from 30 years ago). What's the point (for them)?
Basically, (IMHO of course <g>) it's a pointless and disgusting waste of the worlds resources and a financial burden on those who often can't afford it (postage and cards). If you actually *want* to keep in touch with someone, do so (visit, letter, email, social media, telephone call) and not just once a year?
Cheers, T i m