Considering that the promotion strategies adopted by the platform can increase consumer expectations, the paper constructs decision models for the platform profits maximisation problem and analyse the optimal advertising volume, optimal pricing and optimal promotion strategies of the platform. The results show that the platform is able to influence advertising volume, pricing, or market demand through its promotion strategies, thereby increasing the video profits. Before the video is launched in the market, there exists an optimal promotion period and an optimal allocation proportion of promotion investment. The optimal promotion period before the video is launched in the market is the same under different business models. The optimal promotion investment before video launched is the largest in paid model, the second largest in mixed model, and the smallest in free model.