Hi my friend,
To begin with, its very essential to understand the idea which is behind that request. It needs to be emphasised that neither a sexual pleasure nor your partner satisfaction necessarily depends on the penile size.
Secondly, I highly recommend you not to accept the words of any advertisement. The urology text books strongly believe that there is no oil, cream , tablet or exercises apart from plastic surgery to improve the penis size. Therefore, be cautious not to be cheated!!!
I am a Medical Doctor