Some of the informational stuff (eg about song origins, or different forms of words) is truly wonderful and one of the great things is the ability to get information from all of the main English language nations, which sometimes can be of great help. The Digitrad is a resource beyond price.   

I do however think that another strength is the ability to notify a large possibly like-minded group of events: you never know who might be passing and be able to drop in. Certainly when my wife Jacqui died I had people come both to her wake and the barbecue deathiversary who I would not have been able to inform without mudcat, and who would have had no likelihood of searching the internet for a website of announcement, and I was very happy to be able to make a contribution out of the proceeds of her life insurance. Likewise I would be unaware of Wheaton Aston this weekend, which I happen to be passing, well away from my home, without the Mudcat.