OK – there's a huge risk here that I'm going to put quite a few noses out of joint – including a number of people I know personally.

But I'm going to give it a go anyway. The following is my personal list of the most influential writers, advisors and consultants to the professions – particularly when it comes to strategy, marketing and business development.

I've gone for a global list rather than people who have had an influence in specific countries or specific circumstances.

And please, please, please – if you expected your name to be on the list and it isn't – I can promise you, it'll be an oversight rather than a deliberate slur. My memory just isn't so good nowadays.

The list is in no particular order.

1. Well, I said the list was in no particular order, but who better to start with than David Maister. Since the publication of Managing the Professional Service Firm in 1993, he's been responsible for pioneering or popularising countless ideas and principles which we now take for granted. Now retired, his body of work (including First Amongst Equals, The Trusted Advisor, Practice What You Preach, True Professionalism and Strategy and the Fat Smoker) and the impact of his personal influence mark him out as the most influential contributor to the professions over the past two decades.

2. Ford Harding literally wrote the book on Rainmaking (as well as Cross Selling and Creating Rainmakers). Harding's work is characterised by deep, insightful thinking. You won't find simple “one size fits all” remedies in his books. What you will get is experience, research and critical thinking combined to allow professional firms to develop the unique strategies and approaches that will work for them.

3. After co-authoring The Trusted Advisor with David Maister and Rob Galford, Charlie Green has gone on to make the “trust niche” his own. He's broadened his scope by publishing Trust Based Selling, and has become the leading commentator on the importance of trust in business relationships.

4. Alan Weiss is perhaps best known as a prolific author and advisor to the independent consultant sector. But his contributions to the professions go way beyond that. He's published on management, recruitment, work-life balance – and he led the field in driving for value-based fees. He's often controversial – but always worth paying attention to.

5. Bruce Marcus was writing a blog way before any of us knew what a blog actually was. As the author of 15 books from Competing for Clients back in 1986 through to Client at the Core in 2005, and as a Marketing and Public Relations consultant to some of the leading accounting, law, consulting and financial firms, he's been at the forefront of both defining and implementing leading techniques in Professional Services Marketing. He was one of the early pioneers who highlighted the real differences between services marketing and product marketing and has continued to bring new insights and ideas to bear to this day.

6. Sadly the only female in the Guru12, Suzanne Lowe focuses on the gnarly issue of Marketing Integration: how to get marketing and sales, and professionals and staff aligned and working together on business development challenges – rather than taking refuge in their comfortable silos. While many of us focus on the perhaps more straightforward issues of helping individual professionals and practice areas improve the way they market and sell; Suzanne tackles the sort of problems of cross team and cross discipline integration that bedevil large firms.

7. Like Charlie Green, Andrew Sobel is an ex Gemini Consulting VP and expert (or Deep Generalist as he would put it) on Client Relationships. Sobel's work has focused on how professionals can build trusted advisory relationships with their clients. Latterly, he's explored how relationships can be deepened beyond individuals to allw teams and entire firms to build long-term partnerships with their clients.

8. Mike Schultz & John Doerr are perhaps the “New Kids on the Block”. As the authors of this year's best selling Professional Services Marketing, they're at the forefront of today's knowledge of “what works”: from social media, to the web, to good old fashioned seminars and networking. And as publishers of Raintoday.com, they bring the leading thinking from global experts right into the reach of practising professionals.

9. Robert Middleton was the first “online guru” of professional services. Focusing on independent professionals, Middleton pioneered information marketing approaches (email marketing, teleseminars, etc.) long before the current wave of “experts” jumped on the bandwagon. And his material remains the best and most versatile resource for the sole practitioner and small practice.

10. Another “New Kid on the Block” who's actually been around quite a while is Michael McLaughlin. Mike wrote Guerilla Marketing for Consultants, one of the most accessible sources which professionals can simply pick up and use. This year he turned his focus to selling with Winning the Professional Services Sale and set about converting professionals from pressing and pushing sales to helping clients buy in a way that works for them. It's a fun read too!

11. Richard Chaplin is a name that many won't have heard of. He's not a famous author or speaker. But over the last two decades as founder and chairman of the Managing Partner's Forum and the PM Forum (for Professional Services Marketing and Business Development) he's done as much as anyone to promote effective management and marketing in the professions. Richard's Linkedin connections list reads like a Who's Who of Professional Services. What Richard doesn't know about networking (and especially about Linkedin) probably isn't worth knowing.

12. The identity of the 12th Guru is up to you. Drop your nominations into the comments box for who you think should join the other 11 on the Guru12 list and I'll create a poll to select the final Guru. Or if you're too shy to comment, drop me an email at ian@ianbrodie.com.

PS Thanks to Mary Flaherty of the Raintoday Rainmaker Blog for inspiring this post with her recent excellent posts on the “Best of the Decade” in Professional Services Marketing & Sales.