The first text message advertising hit our mobile phones about two years ago and now we are due to be bombarded with unsolicited texts, whether we like it or not.

The trouble is advertisers now know direct marketing through the short messaging service (SMS ) really works.

To test theories put forward by the wireless service providers, 35 large organisations, including Cadbury's, Carlsberg, Tango, Amnesty International and Capital Radio, pooled their resources to conduct a five-week trial into the efficacy of direct marketing by SMS.

Initial results were extremely positive, with users responding to between 10 per cent and 28 per cent of adverts, well above response rates for conventional direct marketing.

The trial, among 1,000 16 to 34-year-olds, was carried out by wireless marketing company the Mobile Channel, which will launch the initiative to the public next month.

It will send participants three messages a day from advertisers whose products and services match the personal profile of the consumer.

In return, the consumer will get 5p per message and can choose to receive the reward in mobile phone air time, WH Smith vouchers or to donate it to charity. A year of messages adds up to £50.

NOP surveyed 138 of the trialists to gather initial results. It found 80 per cent looked at the messages as soon as they were received, 72 per cent read 76 to 100 per cent of the messages in full and 77 per cent agreed the adverts were interesting.

I wonder how they will feel after a year of checking their inbox and deleting hundreds of Viagra adverts?

The news is not entirely bad as charities (previously hardhit by the lottery) stand to benefit from this digital windfall.

The charity donations service will be launched next month and Amnesty and Childline have already signed up.

In October, the service giving air time and WH Smith vouchers will go live. A £5 million advertising campaign will kick off in October and the service hopes to have 500,000 consumers signed up by the end of the year.

Despite having started off as a niche market, it appears many large organisations now want to jump on the mobile advertising bandwagon as they see texts as a great way to get inside a person's head with their messaging.

Personally, I am convinced that the novelty will soon wear off among users, who will continue to be targeted by an ever-increasing number of advertisers.

As the number of campaigns increases, it will become more and more difficult to evaluate how effective they really are.

Nevertheless, many major players believe there is big potential for the market to produce even greater returns.

There are several issues that need to be addressed if this service is to gain acceptance from the mobile phone user.

There must be clear opt-in and opt-out routes for users so people are not forced to receive messages they do not want.

Databases of telephone numbers must be kept up to date, secure and treated with respect by operators.

Spam (unsolicited mail) is unacceptable, no matter how it is delivered.

Other relevant issues relate to the plethora of handset standards around the world and the obvious limitations of SMS (only being able to send 160 characters).

According to the experts, these will be overcome as the next generation of hardware and messaging services is introduced.

According to O2 and other service providers, pictures and graphics via SMS will soon be widely available and these will almost certainly improve the messages companies want to send, giving advertisers even more scope.

Don't you just love technology?