What has led to the fact that the sphere of services has become the most important factor resulting in the GDP growth in majority of countries at present?

Services is a field, which analyzing the thoughts as well as researches made by different professionals in the sphere of economy is something inevitable for the existence of each country. It is connected with the fact that thanks to the series of various changes and progress its role in terms of contributing to the total GDP growth in significant number of countries has substantially increased.