What were the reasons why Germany annexed Cameroon?

German traders have been involved in trade with West African peoples in the area that later became Cameroon since the late 1860s. The British presence dominated along the coast, but in the early 1880s France was expanding its West African colonial holdings. The development of international trade was destabilizing the existing regional social hierarchy and undermining the power of local chiefs. Several chiefs wanted Britain to annex the area in the hope that it would protect their own authority against possible challenges within their own communities or from the French, who tended to replace local rulers with colonial bureaucrats. British government opinion on this was divided. While British government representatives in West Africa actively worked to prepare for annexation, some high-ranking government officials in England opposed the idea. Disappointed with British vacillation and delays, a few chiefs turned to Germany to ask for protection against the threat of the French advance.
In the 1870s, Germany had not sought colonial expansion, but by the early 1880s the atmosphere changed. Bismarck’s turn to economic protectionism in 1879 and the rapid growth of overseas trade made it more important to secure access to both markets and sources of raw materials. In the early 1880s, influential German organizations began advocating imperial expansion in Africa. In 1883, the German government asked German merchants their opinion about the development of West African trade; the merchants complained about British and French competition. As a result, Bismarck ordered his local representative, Dr. Gustav Nachtigal, to proceed with the annexation. Annexation made Germany into an active participant in the "Scramble for Africa" and set the stage for Germany to play a central role in the diplomatic negotiation of colonial borders in Africa at the Berlin conference of 1884.