1. The market demand
2. Customer's need
3. the regulation of the government.
actually as long as it is non-living thing, we should use "of" 如 the children of the school, the new policy of the government etc. 不能 the school's children. However, when it comes to oral language, we tend to simplify the language even though it may not be grammatical. For instance, we will say "the governement policy has changed recently." instead of "the policy of the government has changed. "