Welcome to the Q&A Forum

Extensionless URLs are a good idea because it helps with unavoidable future platform transitions. If you switch server technologies, you might end pages in .jsp or .html or something else.

Search engines generally consider every character when determining separate URLs. This goes for adding .html and even capital letters. Therefore, these two URLs are different in the eyes of search engines:

www.example.com/page.html

www.example.com/page/

But to really answer your question, adding an extension should have little to no effect on page authority. Search engines are more concerned with your page's content, relevancy, popularity, authority, etc.

This came up in our company recently, too.

I personally dislike special characters in any web copy, be it page titles, meta descriptions, product descriptions, etc. Even though it's anecdotal, I tend to not click on any links with special characters.

I'm pretty interested to see whether testing proves me wrong, though.

This is causing some hand-wrangling and I need some help.

Let's say we were developing rich video content for our products and our agency is hosting the content on a new external server. There are already plans to link to these videos from product detail pages, category pages, and landing pages on our main website: www.example.com.

Would it be better to create a new subdomain or to use a subfolder with a reverse proxy technique for this video content? It's not truly a microsite and will not have a gallery page to navigate the various videos.

For example, would it be better to use this: video.example.com/

...or this (executed with a reverse proxy www.example.com/video/

Of course, regardless of whether this new content will live on a subdomain or within a subfolder, we plan on creating a video Sitemap using guidance from Justin Hammack in this terrific post.