The mobile miner is really for people in developing worlds that do not have a bank account or a computer, but they do have a phone. In this area of the world their phone bill is approximately $3-4 per month. By earning free ETN they can then spend this with the Telecoms company that recommended them in the first place to purchase top up cards. In the developing world $3 per month is a significant amount of money. They will then tell their friends about it and they will then also be able to earn ETN, just from their phone.
The idea of the mobile miner is not that you are actually mining because that isn’t something that would be possible on a phone but by providing people with a mining experience which provides them with ETN that firstly gets them interested in Cryptocurrency but also provides them with a currency that they can purchase things that will make an impact on their life.