I think It will be a mistake to underestimate Airtel after Rene mezas exit (Mind you I am a safaricom die hard)
IF I was the owner of Bharti I would have done the same thing(let meza Go) for one, his marketing strategy was below par actually I thought he was using airtels money to promote a rivals brand..using green color in his adverts to mock safaricom subscribers hurt Airtel more than it built it.
Looking at the current airtel adverts you can notice a big change in strategy...FT reported sometime back that the son of Bhartis chairman(his immediate heir) resides and works in Nairobi and am sure he had something to do with the change over.
If I was safaricom I would be very wary of the current changeover.
'......to the acknowledgment of the mystery of God, and of the Father, and of Christ; 3 In whom are hid all the treasures of wisdom and knowledge.' Colossians 2:2-3