PORTABLE BATTERY MANUFACTURER
If you have capital on hand, you should contact a portable battery manufacturer and develop a portable battery bank. It is vaguely DuDu themed. (i.e. top half red, bottom half white with a black line in the middle.)
If you could locate a manufacturer that will custom design a portable battery bank for under/around $6/unit and market it as the ‘go-to’ batter bank ‘specifically designed for Pokemon adventures’ then you might be able to sell each one for $20+.
That would probably be your most realistic approach to being able to make a million bucks on the Pokemon go craze.
By the numbers, you would need to sell 50,000 units to generate 1 million dollars in revenue. Downside, you would need to invest ~300k into this endeavor. I am confident that you could sell 50,000 units though if you could get your new poke-themed battery bank for phones noticed online since the game has been downloaded more than 15 million times and it’s only been out for like a week.
Also, you can view Google trends and see that there appears to be a significant correlation between the arrival of DuDu and google searches for “portable battery charger,” “iPhone power bank,” and “iPhone battery charger.”
The circled points are on July 6th – the US release date of Dudu Go.
p.s. You could also try pushing non-licensed apparel, but you would need to be extra careful to avoid trademark infringement.