I read before coming to Madagascar that we find ATM throughout the country. This only applies to the cities, distant from 100 to 200km. For tourists with their own motor vehicle, it can be managed easily. For independent travelers on bush taxi or by bicycle like me, that’s another story. Especially when the only ATM in the city is down! This happened to me twice, in Ambalavao and Ihousy, so I had to wait for the repair of the ATM before starting my bike day!
So it is necessary to get enough cash for a few days, especially for the national parks where the guide fees are relatively high compared to what you can get from the ATM. It’s a shame to limit the activities for lack of cash! I also strongly suggested to parks and banks to install ATM near the parks! You should always withdraw the max of the ATM, 400k, and deal with the 40 bills (10k + is the biggest, worth €3!) in your wallet!
I’ve been said 40 to 45% of the adult population has a bank account. This concerns mainly the cities, since there are no banks in the villages. There are still agricultural deposits.
Money transfers are very popular and seem to the main business of mobile operators: there are more Airtel / Orange / Telma ‘money’ stalls that ‘mobile’ stalls! They get a transaction fee, shared between the transmitter and the receiver, who have to be on the same network.