Neither does what Adsense does per se. What Adsense does is it reads the content of the page, and loads relevant ads from from its database of ads (things people put in adwords) and from GDN (also things people put in AdWords, and DBM, only they're pictures). The GDN bit has always been a bit icky IMO.
So, no, they aren't alternatives. Chiticka and others WERE alternatives, but there was a quality control issue (also supply side issues, because Google is a HUGE brand) which led to their eventual demise and/or pivots to waaaay dodgier practices like popunders.
- Targeted by Mike Smith https://www.amazon.com/dp/B00KVO2CGU/ref=dp-kindle-redirect?...
- Google publishes a lot of material https://www.thinkwithgoogle.com/topics/advertising.html
- this is the website of one of the main industrial bodies in advertising http://www.iab.com/insights/?topic=global/
> all alternatives have either lower revenues or the shittiest ads ever
or both...