Here's a selection of features and appearances in the German-speaking media.
Berlin Valley, September 28, 2018
Die Welt, September 19, 2018

Sistrix, February 26, 2018

K5, January 25, 2018

K5, January 23, 2018

Lead, January 3, 2018

Sistrix, January 2014

Deutsche Welle TV, March 2013

February 2013

February 2013

IHK Berlin Magazin, January 2013

Berliner Tagesspiegel, November 24, 2012

eTailment Map, November 2012

Sueddeutsche Zeitung, October 6, 2012

Internet World Business, August 2012

Website Boosting, August 2012

Focus Online, June 2, 2012

Focus, June 4, 2012
Article by Olaf Kolbrueck, Horizont.net, April 19, 2012

A rather unusual mention that I still find amusing came in the context of the SEOktoberfest.

iBusiness, May 2011
The magazine iBusiness wrote a long article on the theme of international SEO.

Telegraph, March 2011
The British daily newspaper The Telegraph published a list of the most influential tech investors in Europe in March 2011. The survey was based on Twitter data. Here is a copy of the article in case it is no longer online.

May 2008
In the May 2008 issue of the iBusiness Executive Summary journal, there was a report on venture capital in the German Web 2.0 market which included an investor map. Various business angels and their holdings in Germany were evaluated.