About 2018-01-23T13:38:56+00:00

Our philosophy

Targetting the professional training of executives, companies, and individuals, LEADER SCHOOL creates leaders in the fields of Social Media and Internet Marketing through effective training processes, services and coaching sessions that provide targeted, practical and meaningful knowledge and solutions.

Why we created Leader School

At a time when Digital Marketing is widespread, there is a need for efficiency.

At a time when there are dozens of theoretical, “university”, “conference style” seminars, there is a need for practical knowledge that can be implemented today and bring results.

At a time when everyone claims to be an instructor and doesn’t focus on offering knowledge but rather on promoting their services as the solution. There is a need for training by an exclusive professional trainer that combines high experience, technical excellence, and transmissibility.

At a time when they say that many hours are what you need and fill their seminars with breaks, jokes and lunch breaks there is a need to invest our time properly and make every minute count. We want to eat and laugh with our friends and our families, not in a professional seminar.

At a time when the level of Digital Marketing is so low with dozens of companies selling useless programs, there is a need to improve the knowledge of professionals and to raise the bar along with their earnings.

At a time when “schools” and “universities” offer everything under the sun and focus on being cost efficient, there is a need for specialization in a single industry. Here we do not create secretaries, nor accountants, nor economists nor are we a bank, our goal is for you to learn Digital Marketing and we are true to this philosophy from the first to the last second you are with us. We have designed everything with an emphasis on the details that will help you truly learn how to apply Digital Marketing.


Over the past 11 years, we have worked with dozens of companies and executives from the field of communications, media, commerce, technology, telecommunications, medical, tourism, the arts, politics, providing a range of consulting services and solutions to various industries.


LEADER SCHOOL leverages the experience gained from all these fields to offer you insights from our long experience and solutions that will help you stand out in an online environment. Some of the people we’ve worked with talk about LEADER SCHOOL.

I’ve had the pleasure of attending the Social Media & Internet Marketing Master PRO. I have attended some seminars in my 20-year career as marketing aAris Pilitsopoulos

Aris Pilitsopoulos • Athens Medical Group

We cooperated effectively for the social strategy development of a brand station in food industry sector

Christos Prapidis • Marketing Manager | Delivery Hero

I have attended Social Media seminars that helped me to understand the opportunities that social media can create in the development of a company

Yota Thomou • Head of Direct Advertising | Primemedia

Social Media seminars helped me to develop our social media strategy on Facebook so as to launch effectively our new mobile devices campaign

Aggeliki Mastori • Marketing Excecutive | Crypto Technology

The seminars I attended in Leader School were very useful. I learnt a lot of smart tricks for today’s digital marketing word. The instructors were so well

Maria Tsagalis • Marketing Manager | HATS (Hellenic Air Training Services)

I have had the distinct pleasure of attending Leader School’s “Digital Marketing Master Business Training Program” conducted by Simos Kosmetatos. Simos has been more than the ideal

Iro Akrioti • Retail Marketing Executive | iStorm

We attended SEO & Online advertising business seminars that resulted in better ranking in Google search engine organic results and better ROI in our advertising on Google Adwords reducing

Mina Iliovits • Marketing Εxecutive | MidEast Travel

We cooperated effectively to create a new online web property around technology and unique online content that was highly appreciated from the online advertising market

Nektarios Sartzetakis • CEO | Nemo Online

We want to thank Simon for the co-operation and the professionalism in Social Media Coaching all these years.

Spyros Papadatos Regional Marketing Manager | Dell

Excellent instructor with perfect business acumen. Trust him!

George Papandreopoulos Capella - MCN (IPG Network)

Simos is a well organised trainer and makes communication in digital era an easy to do task. His skills are deriving from years of experience in the communication field and his ability to transform his knowledge to practical examples. His training on social media was really helpful for me and my work.

Efi Kontouli Marketing Manager | iSquare SA (Apple Reseller)

I’ve had the pleasure of attending the Social Media & Internet Marketing Master PRO. I have attended some seminars in my 20-year career as marketing and communications professional and I must say that Simos is perhaps the best instructor, teacher and strategic thinker. He is passionate about social media and he is well informed of new and emerging communications tools and strategies. I would highly recommend him to anyone interested in learning more about online communications.

Virginia Apelatou Marketing & Communications Manager | QlikView

We have a valuable cooperation building brand awareness for social media customers.

Andreas Vouros General Manager | Bakers Digital Communication

We cooperated with Leader Online School to develop the social media strategy of different brands in the food & retail industry.

Ilias Pantelopoulos Digital Strategist & Entrepreneur

An excellent cooperation that resulted in valuable content creation for different brands in multiple social media platforms. Leader Online School is an important source of new ideas and tools to build your digital marketing strategy. The consulting services gave us new tools and opportunities to reach our target.

Maria Kofou Social Media Strategist

We have a creative cooperation, Simos is a valuable Social Media Coach. Following the coaching sessions, I developed the online strategy of different clients in the health and retail market.

Koni Karabetsou Social Media Expert

Leader Online School’s Internet Consulting services helped our company to develop our online presence building new online sales channels for our products.

Vasilis Papadopoulos Entrepreneur/ Merchant/ Victoria Athens

Following the tools and strategy of the “Social Media Marketing” seminar, I managed to create an effective online strategy and promote my newly created company.

Sofia Kabanidou Managing Director | Fantastick

I have attended Social Media & Internet Marketing Master PRO seminar. The 15 modules of the seminar were excellent and targeted to online success. Mr. Simon Koss, my coach, is an online marketing insider, great professional and always available to you whenever you need him. He helped me create a competitive online presence and, the most important achieve sales and growth. I am really pleased of the seminars and i would highly recommend him to any entrepreneur.

Georgia Giannopoulou Entrepreneur | Health Industry

I attended Social Media Marketing seminars so as to better understand the strategy I need to follow and the tools I should use to increase sales in my eshop in the beauty sector.

Vasiliki Papadopoulou CEO | MakeUpHouse

Excellent cooperation using the Internet Consulting services to understand the internet strategy I should follow as a dentist.

Panos Mitropoulos DDS,MSc Dentist Surgeon

I attended seminars in Social Media, it was great because we had a lot of examples of how to use the tools for my online presence. I am pleased about my cooperation with Simon Koss who helped me to understand how we can use social media in our everyday business life.

Efi Vraka Athlete/Model/Entrepreneur