It should be formal. It is equivalent to a part-time agency. It provides you with part-time information, but this information is not free and you will be charged. I have heard of Chuangcheng, but I personally advise you not to go. Ask if there are any clubs at your university that provide free information. Our school has it, but the school does not provide as much as those intermediary companies.

So think about it yourself, each has its own advantages.