The series of 22 weekly videos to mobiles, designed to prevent teenage pregnancy have been severely criticised by The Taxpayer's Alliance. Based on figures from the BBC, the Department for Children, Schools and Families (DCSF) initiative cost £45 per subscriber as only 5,576 had registered for the free downloads. The DCSF countered by saying it was only a trial and the figures didn't take 83,000 youtube views into account or the 265,000 visits to the website. However, a conversion rate of 2% is disappointing.

The DCSF is right to test new approaches, especially to hard-to-reach audiences. But are Government educational videos really the best thing to send to kids' mobile phones? How hard are they to view on a tiny screen that's been through the washing machine a couple of times? How much would anyone want to follow it after the novelty's worn off? Are kids in deprived inner cities really likely to sign up? Even with the faux teenage txt spk on the homepage? Are the scripts as authentic as The Inbetweeners? Teenagers instantly spot a 'fraud'.

The campaign was produced by leading digital agency 20:20 London. Would a more traditional DM agency steeped in a culture of test, refine and roll out have recommended this campaign? Many digital campaigns are still technique-driven rather than based on sound ROI principles. To only distribute 5,000 of anything free is not a great return, especially if you've spent £250,000 doing it.

For instance, on these figures it would have been cheaper to phone everyone up and have a chat about their sex lives. Or send them loads of free condoms. Surely a sassy viral, along with some deft deployment of social networking and a reality TV celeb to get it off the ground would have reached more teenagers? Even a few witty txt msgs would have done the job better.

But I doubt the Taxpayer's Alliance would buy that either. After all, they oppose all tax rises as a matter of principle, even if they might pay for a better NHS, more people surviving cancer, better educated kids or safer streets. They are they Daily Mail in finance format so anything that upsets them must have merit. And hey, we've all learnt far more from campaigns that bombed than those that worked. So well done DCSF for trying, but next time work harder on the maths. See me after school.