12. The method of claim 11 , further comprising: setting at least one of communities joined by the user, the at least one neighbor, and communities joined by the at least one neighbor, to be a personal network of the user.
12. The method of claim 11 , further comprising: setting at least one of communities joined by the user, the at least one neighbor, and communities joined by the at least one neighbor, to be a personal network of the user. 13. The method of claim 12 , wherein extracting information corresponding to the at least one neighbor comprises extracting information corresponding to a first neighbor having interests corresponding to the interests of the user, and extracting information corresponding to an N th neighbor having interests corresponding to the interests of the user, and wherein N is a real number being equal to or greater than 2.