Katy Perry attacks Britney video?

Katy Perry has hit out against Britney Spears' video for 'Hold It Against Me'.

The singer attacked the use of product placements in music videos, which has been seen as a reference to Britney's use of products in her 'Hold It Against Me' promo.

Marina Diamandis (from Marina and the Diamonds) Tweeted: 'What is consensus on product placement in videos? As a fan, do you prefer product placement if it means bigger buget vid?'

Katy replied: 'do it w/style & grace...Not so in ur face like some. U hv to get creative w/it.Some artists don't care tho, & u can tell'.