This is supposed a neutral collection of facts, purely for informative purposes. Own research, using mostly official company homepages, Wikipedia (both English and German), LinkedIn and archive.org to view older versions of official company homepages.
Gamigo was founded in 2000 in Hamburg, Germany as a professional online gaming magazine and community platform - in direct competition to Gamestar and PCGames. Unlike Gamestar and PCGames they never released any print issues though, and remained an online-only magazine.
Very soon after the initial founding, Gamigo attracted funding through two venture captial firms. Next to their gaming magazine core business, they started renting out game servers for first person shooters, especially the original Counterstrike (the Half-Life mod). They even named their brand "Gamigostrike" - that's how central those Counterstrike servers were to their server business.
They also provided (German) online communities for various games, although for the most part those were fan-managed websites and forums. Gamigo provided free hosting for those fan-sites and in return placed advertisments on those sites - but the all the content, news and moderation of those sites was typically unpaid volunteer labor. Gamigo earned somewhat of a notoriety in the German gaming scene after "overtaking" and "commercializing/destroying" several pre-existing gaming-communities and fan-sites.
In 2001 they started purchasing rights/licenses for publishing existing games into the German market (providing translations and servers): The 4th Coming, Anarchy Online, Puzzle Pirates, Last Chaos, Fiesta Online - while also acting as a publisher to some German developers, for games like Cultures Online and Ufo Online.
They initially started to sell subscriptions, but eventually switched to free to play models for all of their games, with players reporting varying degrees of aggressive predatory sales practices in their games.
It wasn't until 2008 that they started expanding in the EU, and servicing other languages than just German - starting with French and Spanish. By 2013 they also started buying licenses/rights for publishing games to the American market.
After multiple series of mergers and acquisitions throughout Europe and Asia, their 2018 acquisition of Trion Worlds marked their big forage into the American market. Soon after that, they went public (IPO) in 2019.
Gamigo is an investor oriented company, that creates value for shareholders through acquistions of fast growing companies. At least that's how they present themselves in their press releases.
They even proudly present their acquisitions in the about section of their homepage: https://corporate.gamigo.com/en/about-gamigo/#aquisitions
List of mergers and acquisitions (as far as could dig out):
.) 2008 Gamigo itself is acquired by Axel Springer AG
.) 2011 partial acquisition of OnsOn Soft, Korea (Fiesta Online) - could not find any hard info. Company homepage first appeared in 2007 - and finally disappeared in 2019 (but may have been abandoned before that)
.) 2011 partial acquisition of Reakktor Media, Germany (Neocron, Black Prophecy), founded 1991, shut down in 2012
.) 2012 Axel Springer AG sells Gamigo to strategic investor Samarion
.) 2013 (through a subsidiary) acquisition of gulli.com (IT community), founded 1998, shut down 2018
.) 2015 acquistion of next idea GmbH, Germany (online gaming community/portal looki.de that dabbled as publisher for browser games) - founded 2005, current status unclear, but seems to be an empty shell company now. looki.de redirects to a looki branded marketing landing page for a selection of gamigo games.
.) 2015 acquistion of GameSpree, Germany (mobile+browser game publisher, Kings & Legends, WAR2 Glory) - could not find any useful information on that company. webpage appears first in 2013 and was replaced with a redirect to looki.com in 2017 and later gamigo.com
.) 2015 acquistion of Infernum Games, Germany (Online games publisher) - could not find any useful information on that company
.) 2015 acquistion of Mobile Business Engine, (mobile in-game payment provider) - again, could not find any useful information on that company
.) 2015 acquistion of Poged, Germany (browsergame portal selling their own game currency) - again not much to find. website appeared in 2013 and disappeared in 2018.
.) 2016 acquistion of Aeria Games, Germany - (browser games, mobile games, online games) - founded 2006 in USA but ended up headquartered in Berlin after multiple mergers and acquisitions. Got immediately restructured as a Gamiga subsidiary, letting go of 40% of staff.
.) 2017 100% takeover of Mediakraft Networks GmbH, Germany (multi-channel-network with some bigname german youtubers signed on), founded 2011, shut down 2021
.) 2018 acquisition of Trion Worlds Inc., USA (Trove, Rift, Defiance), founded 2006, shut down 2018, 4 days after the acquisition
.) 2019 acquisition of WildTangent Inc., USA (game service company, especially ingame-ads for mobile), founded 1998, now subsidiary
.) 2020/2021 acquisition of Verve Wireless Inc, USA (according to gamigo's own press release) - could not find any information on them. there's only a "Verve Group", which fits the bill - but their homepage claims to be owned by someone else.