In fact all the artists in the top 5 have made an appearance on the X Factor. It is excellent promotion for a new album whether you like it or not.
Of course it's not just a hit because of the programme. It's a great package of the best of Queen's Hits and fans will buy it anyway and this time of year it makes an excellent Xmas present for the everyday music lover.
x factor certainly helped promote AG but i bet they would do well even without it, they'd go probably top 10. don't forget they are one of two most popular bands in UK ever (beatles and them) and people love those kind of compilations even though many of them have GH 1,2 & 3. casual fans won't mind another compilation like we die hard fans