Also, how would you feel as a journalist if the investigative piece you'd spent the last three weeks on was ultimately riddled with "buy it now"s?
Note that this is in the Style section, and they may draw a line between "serious" reporting and entertainment reporting for the purposes of in-line ads.
For now...
- generally the information / buy it now link isn't of interest to readers
- more useful generally would be a link to an internal encyclopaedia page: give the reader more information about the company/book, and include stock quotes / buy it now links on that page
- if it's truly useful enough to include inline in the article, the journalist will put it there manually
- a middle ground would be to pull stock quotes / buy it now links out of the main text into the margin