… In the course of 12 months the concept of the invention was refined. Security specialists and computer scientists ran a technical feasibility analysis. Computer scientist Jens Wiatrowski laid the foundations for the program. It was he who converted the idea into algorithms and programs.

Having defined the characteristic features and the technical realization, Holzer and Wonneberger made sure to apply for a patent for their invention. The general opinion that software cannot be patented did not put them off looking for alternatives. After several months of recherche it became apparent that the software concept could be converted into a process. Devices and processes can be patented. Holzer drew up the patent from 1998 to 1999. The patent "Devices and method to individually filter information transferred by a network" was applied for in September 2000.

From 1999 to 2000 the technical realization of the data filter followed. It was developed entirely inside the company without partners. In order to avoid the idea being copied, the solution was not made public at first.

In 2000 a test run was carried out under real-time conditions at www.adstop.de. The freely accessible application filtered ad banners from the data stream. The users did not have to install any software. All they had to do was to change the proxy server of their browser to Adstop. A survey showed that 85 percent of the users had the impression that Adstop speeded up surfing the internet.

In March 2002, the patent office in Munich finally granted the patent after a year and a half of processing. The patent office confirmed that the invention of a content-related filter is unique both in Europe and the USA. In addition to the core technology – the data filter – three more patents have been applied worldwide.

Over more than 5 years the objective of building the data filter has been pursued, even though the technical feasibility was not sure at the beginning. Now Nutzwerk owns with Holzer's invention a technology that is unique in the world. With a market coverage of 30 percent by 2005 and 6 euros per user and year, sales are expected to rise up to 1.3 billion euros.

In November 2001, Nutzwerk has been awarded the special prize for the best value added model New Economy/Old Economy (prize money 10,000 euros, donated by Roland Berger Strategy Consultants) for their real-time data filter.