Social Stats brings back
the estimated size of the audience you could have in that area.
Research book review blogs to determine the type of books featured,
the estimated size of the audience, and the submission requirements.
Not exact matches
With it, you can look for keywords that are relevant to your courses and then
estimate the
size of your target
audience as well as your ad bids.
The upper end
of estimates may be the
size of TotalBiscuit's
audience, although I'd be shocked if even half
of his population cared very deeply about the topic one way or the other — I'd guess probably 10 - 20K hardcore and the low 6 figures at best.