Yesterday, Twitter marked the fifth year since co-founder Jack Dorsey sent the first tweet.

As part of that date-marking, Twitter launched a new website, discover.twitter.com, that’s a focal point for enabling you to learn about how others use Twitter. On the website is a new video (embedded above, or watch it at YouTube) that is another marker – Twitter is now very much part of the mainstream.

This isn’t the type of aspirational video you might expect, showing people in coffee shops (well, at the start it does) or out and about in the California sunshine tweeting on their mobiles. This video is full of testimonials from some people who may surprise you, starting with Richard Branson and ending with Hillary Clinton.

So Twitter is now in the mainstream. Note that phrase which isn’t the same as saying “Twitter is mainstream.” What I mean is that Twitter is part of the mainstream connected landscape now, just like the BBC, CNN and any online newspaper you can think of.

Watch it and see what you think.

Twitter just grew up.