Marketers must go way beyond the current regulations to win consumer confidence in mobile marketing, according to the findings of a study published by txt4ever in association with the Direct Marketing Association (DMA).
The Mobile Marketing White Paper: UK Spam Study polled consumers to identify attitudes towards  acceptable engagement via mobile. Almost 70% of consumers polled are happy to receive mobile marketing messages, and more than half stated that they would welcome SMS marketing messages from trusted brands with sales promotions and offers that they find of genuine benefit.
However, over half of respondents felt that companies did not make the opt-in process clear enough; two-thirds of respondents wanted to choose the time of day they received mobile marketing messages; and the majority of respondents did not know who had contacted them.  
Trust and clarity are key to developing an effective mobile marketing strategy, says Mark Brill, Chair of the DMA Mobile Marketing Council. It's therefore important to be explicit about opting in. Customers who have opted in should be quickly contacted with confirmation of their choices and information on how to opt out. Brands may find that their reputation is quickly damaged if mobile marketing messages are too frequent, sent at the wrong time of day, irrelevant or unclear to the user.
While only one-third of respondents believe that they are increasingly receiving more spam, the report reveals that people are confused about the financial cost of spam. One-third of respondents believe that simply receiving a spam message will result in a charge to their mobile bill, while the same number believe that opening a spam message results in charges.
The report also points to a lack of understanding on dealing with these unwanted messages. 34%  would complain to their mobile operator, 39% would not complain at all, and 51% would complain directly to the company responsible for the message. With 68% of respondents having received unsolicited messages, the report suggests a need for mobile operators to become involved in dealing with spam.
You can access the full report here.