There is little correlation between the domain of a submission and the amount of points it receives on average. (The exception is the more niche posts by more renowned programmers)
The stories don't have to be popular to generate karma, as long as the domains are some articles will get karma from other people submitting the same links and manual upvotes too. Yesterday someone autosubmitted everything a dozen big tech sites published and got 100 - 200 karma without hitting the front page.
