Stack Overflow gets around 7 million page views per day on the weekend, and around 17 million during the week (https://www.quantcast.com/stackoverflow.com?qcLocale=en_US).

Millions seems to be the appropriate order of magnitude here.

There are more than 9 millions of people that write code

I had the opposite reaction actually. You posted that, so I went to find out how many developers there are in the US.

According to wikipedia, there are approximately 457,000 programmers in the US, which seems like a smaller number than I would have guessed. For contrast, there are ~1.2 million attorneys.