Dead simple idea can be done in minutes.
Giffgaff has a Youtube channel called Giffgaff TV, maybe they could do a DNS redirect from giffgaff.tv to the giffgaff TV youtube site? Quite simply you enter the URL giffgaff.tv and are taken to giffgaffs Youtube page.
I did a whois on giffgaff.tv and the domain is already registered with Telefonica UK LTD so everything is in place to do this already. You have a Youtube channel called giffgaff TV, you have the domain giffgaff.tv, why not link the two together?
Takes literally 10 seconds to do
Easy URL to remember and write in the community, can be used for marketing and at the end of youtube videos (for more videos go to giffgaff.tv), only adds to what already exists.