The plus with writing, is there is 4-6billion peeps in the world nowadays. So even if just 1 percent read, that would mean you would have 4 milion peeps payin to read your book!!
In the world today an average of 1.5 billion peeps read,
there are just under 500million in northamerica; And close to 85-90% read.
Those are good odds! Anyone that has an imagination or is atleast some what intelligent, and wants to grow in life, loves to read so they don't just read 1 book. and besides there are all the talk shows now a days. So u should'nt have a problem gettin to those peeps.
My advice don't stick to one genre of writing, try to mix it up. That way you reach more peeps; thats what I would do atleast good luck
history
factual books
-personal learningstories
-self help
-fiction
fantasy science fiction
-adventure
-horror
-mystery/suspense
-scientific books
-world books
-encyclopedia's (if u choose a different avenue in writing, they get paid big bucks to put those encyclo sets together)
and the list goes on..............