According to the Press Release here's what one can expect to earn.

What can you expect to earn?

We will be fine tuning the system over the next few weeks as we see how the mobile miner works with hundreds of thousands of users. We don't know what our "average" user's smartphone mining power is, but we expect users to be awarded a few US dollars of ETN value per month by running the app in the background. It doesn't use much data or battery life, but remember if your mobile data is expensive it is up to you to ensure the mining does not cost you money. Use it on wifi initially to understand the amount of data it uses.

I was initially introduced to ETN by a newsletter that I've been following for years that has a great track record on picking winners. I looked into it a bit further and decided to throw a few hundred bucks at it and pick up a few thousand coins. Should be interesting to see how this pans out moving forward. They've been hitting all of their milestones and we'll see how this roll out goes and what 2018 and beyond bring. :)