Previously I would set the name servers of a domain to what the hosting company told me (e.g. ns1.hostingcompany.com). I've now started buying domains from a company that lets you make your own nameservers (e.g. ns1.mywebsite.com) and I just enter the IP for them (I presume of my webhost server).
My question, what is the point of this? Is it purely cosmetic? (I do find this cool, that I'd have ns1.mysite.com, but I'm a geek, is there any other advantage or disadvantage to this?