That is down to the host. For those that don't know, that is where the site 'sits' waiting for you to look at it. The space is "owned" by a company or person and "rented" to people to place their scribblings for the whole world to see.
I started with the Webspace that comes as part of our (Denise and I) Broadband internet connection package, that is 55MB of space with Virgin Media. This space is advert free but relatively small in size so I needed to have room to expand. I looked around at several options (you may remember that the first one I moved to went 'toes up' within a week of the site move!).
I am now using Free Web Hosting Area as well, which gets payment for the hosting by showing adverts. There is 200MB of space available there and combined with VM makes 255MB of space. I am working at removing the adverts, but the company seems to have a problem processing my payment at the moment! (done Sept 2007).
The visually impaired site resides in the advert free VM space along with some large files that don't like being in the free FWHA space.
Update: 23 Sept 2007. The web hosting on Free Web Hosting Area has now been paid for and adverts should no longer appear.
Update: 27 Jan 2008. The visually impaired site has been removed but the Virgin Media space is still being used for some files.
Update: 24 Aug 2008. FWHA upgraded space to 500MB.
Update: 23 Nov 2008. The whole site has now been moved to the Free Web Hosting Area server.