Not sure where this belongs so if it should be elsewhere mods please feel free to move it. Here is my question for all of you. suppose that I have the domain secrets .com (i don't) and I wanted to start several niche type sites, would it be better to have separate domains for each or would subdomains like this be good? blogging.secrets facebook.secrets moneymaking.secrets and so on
Yes that would be good as well for SEO purposes as long as your doing the right techniques. Backlink the subs with anchor texts and you'll do perfectly fine
Why not inner pages of a root umbrella domain? I mean, keyword.domain.com would be less powerful as opposed to domain.com/keyword if you are looking from an SEO perspective. From the sales perspective though a separate domain *may* (or may not) be better.
I would actually start out with subdomains if I were you. It will save you a lot of money starting out and you can kind of "test the waters" to see what will work and what won't easily without having to keep buying new domains and wasting your money.
I like the idea of subdomains; it would really make your site stand out and offer something unique to your visitors.
Yeah making subdomains of this type should be good if they're somehow related with your root domain name.