As the mobile is a personal and intimate media, everything not relevant to me will be considered as spam respectively as an intrusion into my privacy. Therefore if we talk about mobile marketing, it must be made in a much subtler way than in any other media before. "Participatory media" and "neomarketing" will probably be the best way to go.

The Mobile Marketing Magazine comes to the same results in The Mobile Opportunity

In recent years, companies have dipped their toes in the water, and begun experimenting with SMS marketing, in order to engage with customers via text-to-win, text-for-info and text-for-coupon pilots. Bombarding mobile phone users with unsolicited ‘nuisance’ messages though, has created a serious misconception about mobile advertising and to many this still prevails.

[...] By adding mobile integration to current campaigns, brands can enjoy a personal relationship with consumers no other form of communication can match. To maximise success, it is vital that the right material is presented in the correct manner. Although they are the most lucrative consumer sector of mobile phones, the new generation of 18 to 24 year olds are highly sophisticated, critical and increasingly cynical. Able to shut out anything remotely resembling spam, it is essential that any communications aimed directly into their pockets are innovative, imaginative and relevant, otherwise they won’t opt in to receive this service.