How to choose Shenzhen international SMS group sending?

Shenzhen SMS group sending, affordable is not necessarily reliable, LZ must be identified well, be careful to be deceived, at least go to the cooperative company to see. I worked with a company before, and the price was ok. I also visited their company at that time. All aspects of qualifications are good, licenses are relatively complete, and there are many successful cases of the company, including various industries, such as real estate and automobiles. Oh, by the way, Shenzhen SMS group was sent by Blue Ocean Yitong Advertising Company.