Now, we've all agreed long ago that repeat attendance isn't necessarily 'a bad thing', and no-one really thinks all respondents are virgins, nor do we think the same 37 people go to every group in the country.

The reality is somewhere in between. But where? How common is the professional respondent? Is it something we should be concerned about ­ or are all the recruitment initiatives a sledgehammer to crack a nut? At present we don't really know.

Some insight arises from a paper at this year's MRS Conference ­ Drusilla Gabbott, from AMV BBDO, used a BMRB omnibus survey to find out who had been to groups. It varies massively by region, as the top chart shows. And how many groups had these people been to? The bottom chart shows that in London ­ the most heavily researched area ­ about a third had been to just one group ­ and the final third had been to three groups or more.

On the one hand this doesn't look too bad ­ but as a more numerate friend worked out, this means the average London group has, at most, just one virgin respondent.

While the data is intriguing it is methodologically flawed ­ all omnibus interviews are randomly located whereas groups are highly clustered into tight geographical areas, and who knows what the situation is in these qual havens.

It's an issue that warrants more investigation, and I've been asked by the Commitee to look at this whole area more thoroughly ­ not to make judgements about what's 'good' or what's 'right', just to establish some reliable information. After all, it's quite nonsensical for an industry that exists to provide insight and information not to know what's going on in its backyard. Watch this space.