The difference is that Katy has a good track record with listeners and people who buy music, having consistently released songs they enjoy for over 4 years. Gaga hasn't released a song people want to hear for about 4 years now. It's going to take a hell of a lot more than 1 or 2 people requesting her songs to convince radio stations that they're not going to lose listeners by playing her songs. (Of course there were Applause, The Edge of Glory and Born This Way, but they weren't exactly runaway smash singles, even though most of them came out pre-album.)
Not that any of this has any relevance at all to Katy promoting her songs to radio stations. The cakes are just a clever way to to let them know they have the green light to play the new single now, not a massive plot by the illuminati to hypnotise DJs into spinning Katys songs.
This was the phrasing I was looking for, Benjamin is spot on.
But I do not believe this was Katys idea at all. Going off what I read by the stans on here Katy doesnt care for radio success that much so I'm sure it was her team 100%.