Out of the activities of long-distance trade, many trading centers emerged in the interior i.e. Tabora, Ujiji, Ugawe, Kasnga, Kalanga, Bagamoyo, Panguni, Karagwe, Chewa etc. they grew because of the following reasons;
- The increased participation of the African societies in the interior trade led to the development of such centers. In the spirit of having local trade development, each society in the interior develops its own trading centers which acted as a local market. It was out of this arrangement that make 7 centers turned into trading centers especially with the penetration of the Arabs i.e. Tabora, Ujiji, Urambo etc.
- The increasing penetration of the Arabs in the interiors led to the rise of trading centers when centers won the Arabs entered into the interior. They established centers which gave way for slow urbanization of trade centers i.e. Tabora, Ujiji and Bagamoyo.
- The presence of trade into the interior, it should be noted that each trade route passed through settlements which later developed into large trade centers i.e. in all settlements were the central trade route of long distance trade passed there emerged into trading centers i.e. Kasongo, Tanga, Urambo, Tabora, Nyangwo etc.
- Seyyids arrival at the coast, he sent many Arab caravans in the interior to establish trading posts in order to promote trade act trading centers of the various trading items i.e. Tunga, Pangani, Ujiji etc.
- The rise of African traders led to the growth of trading centers i.e. the rise of Mirambo, Msiri, Nyungu Yamawe, Machemba, Fundikira, Mataka etc. to the growth of centers, Urambo which acted as their operational commercial bases.
- The rise of Swahili traders in the interiors that penetrated into the interior, each established his own trading center in the interior in an attempt to create commercial areas i.e. Mohammed Bin Hamid (Tipu Tipu) established a trading center at Nyangwe while Seyyid Bin Babu at Urambo and Abdullah Bin Nassib established his at Tabora.
- Increased demand for slaves forced the Arabs and Swahili established centers in the interior for collecting such slaves which later emerged into urban centers of commercial activities i.e. Bagamoyo.
- Increased demand for more land for plantation farming among the Swahili traders especially upon setting in the interiors many Swahili and Arab traders began to confiscate or grab land from the interior tribes in order to establish cloves and other clops i.e. rice with the farming activities, trading centers i.e. Tabora and Bagamoyo emerged.
- The need is organized markets i.e. Swahili Arab traders were tired of buying African trade items from individuals/communities. Therefore, they begun to organize village centers that would act as village services with time such places i.e. Bagamoyo, Ujiji and Urambo emerged into trading centers.
- The need for security among traders also led to the development of trade centers. The traders wanted to secure trade centers for their commodities and transactions in order to minimize of most of goods through insecure areas that would deep in the interior trading centers i.e. Kasombe, Bisa, and Karema emerged in Kenya.
- The need of storage facilities i.e. trading centers were established in the interior so as to act as stores for the trade items in the interior. This would prevent goods from getting destroyed during the long distance aim the interior to the coast. Above all using head portage in such areas i.e. Tabora even had dangers in caves that acted as stores.
- The hospitality of African leaders who welcomed the Arab Swahili traders and allowed them to stay with them e.g. Mirambo invited Seyyid Bin Babu who stayed for good and developed trading centers at Urambo.