Please make use of this tip.

https://www.capitalismlab.com/new-conte ... -supplier/

You can change everything at a single store.

P.S. The interface may look different from the screenshot due to patches, but the key point is to use the “Batch” button in the supplier search function.

I checked your save file. Your company is already maintaining 100% Advertiser Shares, including Local Advertisers.

The problem is that your media company alone cannot attract all the advertisements in that city, because the advertising share of your business is extremely high.

In this situation ...

Finally, in your save file, I added four more TV stations, radio stations, and newspaper companies each, and set their CPMs to 10% lower than the AI’s.

After that, the TV, radio, and newspaper media companies you had built immediately ranked 1st, 2nd, and 3rd in profitability. On the other hand ...