Effective method of using many advertising networks

Hi, sorry if i'm writing in the wrong category, i'm new of this forum so first hello to all I'v got a website where i'm using now two ad networks: popads, adsterra. I'm going to add third ad network: revenue hits and i wonder about two variants:
- add 3 codes one by one in footer
- create php code displaying random ad code for every refresh of website.
My average pageviews per user in Google Analitics is about 3.5.
What is the better way and why? I will be grateful for any reply

If their tos accept different ad networks to work with.

Then add all the 3 in the footer, it will maximize your profit 3x than displaying 1 ad.

If you care about your website visitors surfing experience, then use the rotator or remove all your ads