I think the first post here summed it up pretty well...

TRACKING IS THE ONLY WAY TO KNOW.

Like, for some of my sites (over 70) I have articles as the main method of promotion, some are optimized in the search engines to rank high for their search terms. Other's are just getting traffic from video's I've posted on YouTube.

It can depend a lot on what you want out of it. It also depends on the niche a lot.

Like "Knitting" might be hard to write about in articles, but easier to do on video, same with Guitars.

But like "how to write better" is easier demonstrated in text...

See what I'm getting at?

Think about what the customer is most likely to do to try to find you, then go where they are and focus your energy there.

- Chris