AdMob, AdColony, Chartboost and Unity Ads.VS. Other ad Providers

Getting Started Newbie Questions
#1

I was confused in an email from Corona Labs titled “Engineering Update”.

At the bottom of the message it said, 

“Corona Labs offers four monetization plugins that are revenue-share free. You are 100% in control of your dashboard and you get 100% of your revenue. These include AdMob, AdColony, Chartboost and Unity Ads.”

I thought that for ALL ad networks provided by Corona, the developers of an app get 100% of app revenue until they are making over $500,000. Why does it say that these 4 are “revenue-share free” when all ad networks provided by Corona are revenue-share free? I also know that these 4 networks have a yearly fee.

#2

AppLovin and Facebook Audience Network have a 5% revenue share. Basically for every 20 ads you serve, 1 is credited to a Corona Labs account, the other 19 are credited to your account.  When AdColony and Chartboost were part of CoronaAds, we had a 5% revenue share with those plugins as well. We added the new AdMob plugin with a 5% model, but after listening to feed back, we chose to make  AdMob, AdColony and Chartboost revenue-share free but for a fixed up front fee. Unity Ads was added with this model a bit later.  

Today, we have four plugins that you pay for up front, two plugins that have a revenue share split, and the remainder are free to use.

Rob

#3

AppLovin and Facebook Audience Network have a 5% revenue share. Basically for every 20 ads you serve, 1 is credited to a Corona Labs account, the other 19 are credited to your account.  When AdColony and Chartboost were part of CoronaAds, we had a 5% revenue share with those plugins as well. We added the new AdMob plugin with a 5% model, but after listening to feed back, we chose to make  AdMob, AdColony and Chartboost revenue-share free but for a fixed up front fee. Unity Ads was added with this model a bit later.  

Today, we have four plugins that you pay for up front, two plugins that have a revenue share split, and the remainder are free to use.

Rob