First tier platform traffic:
Google ads
Facebook ads
Bing ads
Quora ads
Reddit ads
Second tier platform traffic: (Good for AdSense arbitrage)
Taboola ads
Propellers ads
Adsterra ads
Moneytag ads
Mgid ads
Admaven ads
Third tier traffic platform: (extremely good at AdSense arbitrage because of ROi)
Popads
Popcash
Propellers ads( bit cheap)
Adsterra bit cheap)
If I were you I will start doing the arbitrage using propeller ads with viral or news captivating content. Also think of something like a niche meme.
Something that has the power to go viral or perhaps high CPC content that have the possibility of going viral and can appeal people.