It is very good for affilliates to have there own ECA stores, but only if they have products and services to sell.
I have been an ECA since I started as an affiliate, at the end of the day without a product or service to market there would be no money in the system to pay any commissions or bonuses.
I find being an ECA a very rewarding part of the business and helps to increase income from the business as a whole.