Madonna still is an artist who can have incredible chart runs - Hung Up, Sorry, 4 Minutes are all examples of her latest stuff that have had massive chart runs ..
Celebration however, was an underpromoted song from a greatest hits album that was, quite frankly, underwhelming (albeit an enjoyable slice of eurodance) ... that's a big difference from the likes of Cliff who's fan base (when rallied) can guarantee him a top 10 placing ...
Madonna is an artist who has consistently proved can appeal to the mass single buyers with strong enough material and have decent chart runs ....
Cliff on the other hand is an immensely popular artist who's singles tend to be gimmicky (which is a shame because arguably his last proper singles - what car, I cannot give you my love etc - were actually rather good!) ...