How does Admob determine the textual context to show targeted advertisements?

Question

1) Is the Admob SDK able to retrieve all the text strings shown in a app and display targeted ads based on those?

2) Do I have to specify the strings manually by AdRequest.setKeywords(keywords)? EDIT: setKeywords is ignored. Source

3) The targeted ads are shown based on the application description and title entered in Admob website?

4) Some other factor(s)?

5) Non of parameters mentioned are used and Admob does not provide context targeted ads only region based ads?

Answer 1

It not meaningful to parse the content as a web page on mobile devices, so the answer is no context targeted ads for now. I asked the same question with a googler. His answer is AdMob delivers Ads based on user's behavior. Initially, AdMob delivers any kinds of Ad to you. If you tap the "car" Ads more than the others, it means that you are interesting in buying a car recently, so more car Ads will be delivered to you, something like that.