I have an ESL (English as a second language) business in the Japanese market and I sell learning materials. I used to use 2 big keywords "Study English" and "Learn English" and for both I got #1 (Google Japan), until that ugly Penguin walked all over my site(s).
Anyway, it was a mess for a while but I gathered myself and decided to start up again. Now I learned that it is better to have not only quality content, but also many pages. That would also work for Long Tail SEO.
So, my plan now is to create a website which has good quality information about learning/studying English.That part is probably simple.
My question now is if it is better to stick to one big theme when creating the website. What I mean is there are many sub themes which would lead to sales(I know this through my experience with PPC). For example, "Study TOEIC" "English conversation" ""English idioms (or vocabulary or grammar or whatever)"etc. etc. and I could write about them.
I could make a one big website which deals with all of these themes and topics, or I can divide it into maybe 4-5 sub themes and create a website for each. I hear that Google likes a site with specific theme, in that sense I thought dividing it would make more sense. However they are in a way all related (that's why I get conversions through these keywords), so one big website might make sense too if I think of getting good authority later and stick to one big keyword (Study/learn English). I can still get hits with other keywords through "long tail SEO".
I thought of using sub-domains and it would give me the pros of having several websites and it is easier to manage, however if my domain penalized again somehow, then all the websites would be dead (same as using one domain).
Any thoughts/advise would be appreciated.