You should provide interesting contents on your website which brings your visitors back over and over.
I agree, a good content will make your readers visit your page again, but of course, you also have to find means to promote it depending on your niche.
AdSense alone will never bring any traffic to your website. Any kind of website can attract traffic. AdSense relies on you to bring traffic to your website FIRST. Many SEO and traffic building software/technics are available on the market to achieve it. I personally use Blogs. It's free. Like Technocrati blogging. Good luck. wsjaig.com gynecography.com
Any niche will do it as long you had the following: A custom solution custom softwares good marketing Quality freebies I'm trying to get as much as i can from adsense, but it seems that my thingie was not with adsense Well, if you throw one rock to one fruit on a tree, will only last as long as you throw the rock, but if you try to throw one rock to fruits on the tree, guess what will happen. i mean, don't focus to choose adsense as your main stream of income IMHO
Legal, medical ,loans, credit cards sites are good for adsense but you should maintain it by writing good content and high paying keywords.
As long as you have good content and lots of visitors you will make money. Basically it means creating new (unique) content every day and paying attention to getting links to your site. If you're starting out then chose a niche without much competition (I'm making $300 a month with a site dedicated to the Celtic gods), so as long as you can dominate your niche and get enough visitors just about anything can be made to pay.