OK, The subscriber will pay his fee and 80% goes to the authors and experts and 20% goes to the system. But will the user (simple subscriber) know exactly to whom his money got via using free widget? Maybe he wants to control the percentage of money going to experts or authors? Cause he may distrust widget fund in somewhat way.
The author sets a static fee at widget creation (e.g. if they set a 20% fee, then experts get 100-20-20=60%). Now, calculating how much money each
expert gets is a bit trickier, because the final distribution is resolved at the end of the month, but it can be approximated using the expert's historical (3 months average) rating, which is known at all times.