Microblogging service Twitter Inc. has raised $300 million from Saudi Prince Alwaleed bin Talal. Alwaleed is the richest Arab businessman and he considers the investment as a “strategic stake.” Alwaleed is the largest individual invest in Citigroup Inc. He is also a major investor in General Motors and Apple Inc. Twitter is in the process of revamping their user interface for their 100 million daily active users. Twitter is expecting to boost their ad revenue by about 86% next year.