What's next after AdSense?
It turned out to be that my AdSense account had been suspended for "invalid traffic", whatever it means. It could be someone (could be me or someone else) clicking multiple times the ads on my blog, generating or receiving automated or bot traffic (I am definitely not that sophisticated), or several other reasons that are beyond my comprehension technically.
I do remember that they sent me an email in 2012 I think, saying that my account was suspended due to inactivity. So, the only way was to post regularly. Alas, it became too burdensome. So all my three blogs were practically abandoned in the past few years.
After reviewing those pages of explanations on Google AdSense, I decided that it is almost or nearly impossible to reinstate my account.
Browsing on the internet, I found that actually there are many other services to replace AdSense. Let's try them one-by-one.
But the bottom point is, I need to regularly update my blog.
Let's see how it is going.