The economy of the online portal, how not to go into the red?

Question

Electronic commerce

Good afternoon, the situation is as follows:
There is a catalog portal where downloads are made for local currency, while it can be bought/earned and cashed out.
- Downloading the file costs 10 coins.
How to get coins:
Publish your files in the directory - 10 coins.
For each download of your files by other users - 1 coin.
Write an article or note on the portal - from 50 to 500 coins (upon the decision of the administration).
Buy coins - 10 rubles\coin (minimum purchase is 50 coins, i.e. for 500 rubles)
Write on the forum - 1 coin per message (credited within 24 hours, after moderation).
Cashing out:
- Withdrawal at the rate of 3 rubles/coin;
- Minimum withdrawal amount - 150 coins
Problems
We believe that the budget for adding files and writing articles is unlimited.
But writing on the forum and charging file owners for downloading is a problem.
Usually downloaded 10-50 times (80%), 50-200 times (15%) and more than 200 times (5%).
Those. if there are 10,000 coins in the system, then we consider that this is 30,000 rubles.
If 10,000 coins are spent on downloading, then 1,000 coins will remain in the system.
If 1000 coins are spent on downloading, then 100 coins will remain in the system.
Those. they decrease, when adding content, their number will increase. There is a fear that the growth of their number will be greater than the income from the sale of coins for money. Thus, the hole in the pocket will grow.
What do you think are the weaknesses of the economy of such a project?
Maybe you have experience in organizing such systems, how did you solve the issues of losing money?

Answer 1

Give coins only for downloading.

Answer 2

The issue can be solved by canceling the charge for the forums, but then many who do not want to pay will not be able to download, and the forum needs to be developed.