[timsco]

This struck me as well. Flash's video format, .flv was transparent out of the box and we used to do a lot of fun things with video floating over flash things.

When flash met it's untimely death, the advertising creatives that I worked spent 10 years asking for solutions that involved transparent video in html; we had to tell them no.

I hadn't really considered that browser blend modes have turned that party back on.