Which is more effective - mobile advertising or online advertising?

well it depends who you target, for what product, when… Your question is too broad to be answered.
Try to narrow it down a little bit.

....yes it depends again but also cell phone is more like is going on realtime if u know what I'm talking about like u are in touch but also in a way not be annoying or some kind of spam and include a way to stop receiving or for example ask how many messages to receive and also if u want Extra more offers give ur number to other firms or no in other words more options more optionnal with diffrents choices and different types..