I think that at the time it was a little to pop, unlike Comminucation Breakdown. Of all the Zep. catalogue, I feel this song is the most pop-friendly. But I love it. Perhaps it was about someone he didn't like. It's one of the most catchy songs EVER played by the band, if not the most.
For whatever reason, I think it was a good reason at the time not to play it live or make it a hit. If it had, I feel this song could have made the public feel Zep. was about pop, friendly type songs instead of diversity..which is what Page wanted! I'm happy the band became what they are instead of another Britney Spears!