Quarter bottles would be perfect - splitting a generous single pour for 2 people is an appropriate tasting. We see some half bottles here, and then single serve which are mostly the mass producers. Beginning to see some in aluminum cans, but these seem to be more upstart wineries. Some canned wine has been decent and some has been completely undrinkable. In any case, I think if wineries adapted to the times by producing quarter bottles (and prorated the cost, maybe quarter bottles sell for 30% of the regular bottle), they could be opening up a whole new market both for online tastings as well as people who just want to try wines without committing to an $80 bottle.