They are responsible for around 70% of household purchases and $20 trillion of consumer spending worldwide, and yet, when it comes to engaging with ‘mum bloggers’, the PR industry is quite frankly missing a trick.

Parenting lifestyle bloggers, mum bloggers, women with kids who blog – semantics aside, they have become a well-established source of influence for brands looking to tap into the parent market and a channel and that is increasingly giving traditional media and journalists a run for their money.

But despite being heavily targeted by brands and their PR agencies, communication is at best ineffective and badly targeted, according to research published yesterday.

Collectively the UK blogosphere generates an estimated £21m in fees from brand partnerships, not including the value of free products, experiences and services or indeed agency fees. However, analysis of the sector by BritMums, a collective of parenting and lifestyle bloggers, in collaboration with PR agency Hill+Knowlton Strategies finds that too much of that investment is falling on deaf ears as PRs miss the mark in the fight for a share of an increasingly influential voice.

Interestingly, the vast majority of bloggers – 93% – are certainly receptive to the idea of working with brands and from a PR perspective some inroads are being made in responding to this desire to engage, with half of respondents saying they are being approached more frequently than they were a year ago. Certainly the implication is that a significant number of bloggers offer a perceived “value” to brands, who in return are being more effective and targeted in the way they engage with parent bloggers.

But what of the other 50%? The report warns that despite the growing influence of the market, the vast majority of brands and their agencies still don’t get it when it comes to understanding how to work with bloggers. And according to the report, the list of misdemeanors is almost embarrassing, resulting in the high volume of brand content that heads straight into bloggers’ deleted folder.

Nearly three quarters of this blogger group (71%) say they hear from up to 20 brands a week and yet 78% say less than a fifth of that content ever makes it onto their blog. For a fifth of respondents, none of this brand content gets published.

Other faux-pas include pitching an idea that is irrelevant to the blog (66%), expecting editorial control (33%) or that the blogger will work for free (62%), or the pray and spray approach – 61% of respondents said receiving a blanket, generic email got their back up. More than a quarter said they took offence at being labelled a “mummy blogger”.

With more than a quarter of mum bloggers (no offence intended) planning to turn their blog into a full time job this year, and with the blogger community growing and become increasingly savvy – the message is, it’s time for the public relations industry to wise up to the power of this group, or miss losing out on the prized Parent Pound.