Just adding context (No SEO) = good adsense income?

Theme is the part that does most of on-page SEO. You can improve it by installing a SEO plugin, but well-made theme is enough.

If "by default" you mean "with the stock theme" - sorry, don't know because I try to avoid those. However, I don't have any reason to believe that twentywhatever series would be terrible.

Changing permalinks to /%postname%/ is considered SEO.

Hi Sideburn, I didnt just build a site with 1 page they have around 10 to 15 pages and posts I like to make my sites a complete package so I choose my niche and its always healthcare by the way LOVE that niche and say the topic was `occupational therapy` a niche I actually tried but it proved too tough but say it was I then rack my brains thinking of every question someone looking to start a career in that area would want answering and create a site around it most of the questions are found in a keyword search in google planner sure but I try to think of others and also scan the web for answers to the keywords and link to the pages of other great sites so that my page is really really helpful. I never used to do this but now I really enjoy creating helpful sites,

Ok maybe I was wrong saying I made all the money from just 1 page that may not be 100% true I have afew pages at top 5 positions so theres some traffic there and possibly some longtail stuff I`m dont even know about but the lions share was with just 1 page.

The other thing and this may get ripped to peices by SEO guys on here is... I always build sites on expired high PR domains so I buy a good PR3 domain and build a site on it I`m sure you know that story.. So when my site get hit by the latest google update I use that site on `occupational therapy` as a backlink site to my new site on `occupational therapy` now I question this myself sometimes as the old domain has just been hit by google but I have PR3/4 pages with just 1 OBL pointing to my new site .. for course there on different hosts.

And I`m not sure where that guys gone who says you cannot make money with adsense WOW how wrong can a guy be the adwords click costs are shockingly expensive right by and in healthcare I get $10 clicks all day and as high as $25 !! Google is doing really really cool things with the adsense blocks trying new styles all the time and I promise you I did $4000 last month !

Jim

It's likely that you're not going to make thousands from one site unless you're insanely successful. But that should be obvious. Just pull some numbers out of your hat and make some estimations. What if you get x visitors, y% of those click ads, and you get $z per click? You should know the traffic you've gotten in the best days, and you can find typical CTRs and estimates of average Adsense payouts form the internet.

Some marketers target multiple niches. It allows you to choose the best working niche, and put your effort to that.