The largest Esports annual prize pools are broken down here in USD.
Clearly DOTA 2 is leading with a 2018 prize pool of $25,532,177.00 so the 2019 prize pool will be even bigger.
The online viewer statistics of the annual can be found here.
Total views of all channels is 566,793,964. This is a significant number of views and does not count various other websites that stream these matches such as https://www.esportstv.org/
or ESPN http://www.espn.com/esports/ or any other additional TV or online coverage.
So what if the Electroneum team put up a 10,000,000 ETN winner pot for the DOTA 2 International 2019?
What do you think the impact would be?
Optionally: they could go halves with a mobile carrier and each put up half the prize
or even the mobile carrier could get sold on putting up 100% of the prize
or the mobile carrier could put up a smaller prize for the monthly and quarterly tournaments
or some combination of the above.
A consultation with someone knowledgeable in esports might help, maybe try TotalBiscuit on youtube with 2.2 million subscribers.