Both animations (GIFs) and videos are useful ways of describing Mathematica solutions. I was looking for some guidance as to how big an animated GIF should be when posted as part of an answer. I've not uploaded a few that I thought would be helpful once I realised that the filesize was getting a bit big. It's OK to upload a 3MB GIF in the background, but less OK to have to download an answer with a few big GIF animations on a slow connection. So, if GIFs are not always possible, what about videos...
A more flexible way to include animated graphics on a web page is to have embedded videos. This is allowed on certain StackExchange sites - gaming for example. Presumably these are better for both bandwidth and quality than embedded GIFs? According to this post on MetaStackOverflow, "Embedded videos are allowed on a per-site basis."
I think there are a number of answers that would benefit from videos and animations. I don't think there's any danger of people abusing the system (questions and answers can be edited, after all) - and it would allow people to post more compelling and useful answers. So is it possible to ask for this feature to be added to mathematica.stackexchange.com?