Has Birthday been give a uk release date? I don't think it has. It looks like it has just be put out there. it looked like it would make top 20 after climbing well in the last few weeks but according to this weeks chart update it is now around 33. She hasn't really promoted it apart from her tour which I guess should be enough?.

Birthday is a flop by Katy's standards and it's so basic we could see this coming form a mile off

Legendary Lovers is the next single in The Netherlands (Birthday flopped here) so I imagine the rest of the world wil follow

I've never known of her releasing different singles according to country I know that other artists have done it. I like "Legendary Lovers".

Birthday is fun for a couple of days but then it just washes itself out to forgettable pop. It's too weak of a song.

I do agree with this. "birthday" has grown on me since it's release though.

I adore This Is How We Do. Her performance on it when I saw her live was fantastic.

However I think Legendary Lovers would be the best choice, because it is that little bit left field and incredibly catchy.

Looks like LL is very well liked and I do hope it is a single. As for Birthday it is her 4th single already and its a typical middle of the album promotion type of song. 4th singles are often design to boost albums sales more then anything which it has done. The 5th single should be used to remind everyone of the album and to show the different styles there are on the album so a big promotion push will be needed as well.