I have added an ideapaper detailing how telecom companies find growth. The telecom service provider does not simply grow. These companies transform from voice telephony operators to bandwidth service operators and finally into a holding company for other telecom companies. The following IdeaPaper details those five phases of transformation. I have also given some key characteristics of each phase.
Bharti-MTN deal was example of how both companies were trying to move to phase V of the transformation. As of now France Telecom, Portugal Telecom, Vodafone, Singtel are this phase. I still believe it is too early for Bharti to move to phase V, particularly since there are ample avenues for growth still open to it. Bharti's eagerness to join the club was forced by the fact that telecom is developing globally and soon there won't be many opportunities to get access to subscribers and telecom assets. Anyways the interesting part is how telecom companies find growth.
Further, there are still ways and means to exploit current opportunity for telecom companies. But that is topic for further paper.
Disclaimer: I own Bharti stock.