Perhaps the most common form of generating revenue and why not? Place
some code into your pages and wait for the check each month. Let someone
else worry about brokering the ads and the technical witchcraft. But what if
keeping your website on topic is important to you? What about Japan-related
ads?
The bad news: If you are committed to displaying Japan-related ads in
your website then you are very limited in your ad network choices. Some networks
such as BURST!
advertise that they will provide campaigns targeted to your content. These
are infrequent and the targeted campaigns may be a small percentage of the
total ads.
The good news: There are still a few choices in the form
of content-specific or content-targeted ad networks. Most are text ads with
the exception of Google's recent inclusion of graphic banners.
A more proper title would be "content-specific ad networks" as the
technology used in these networks aligns advertisements to the textual
content of the page on which the code is placed.
Below are three networks
I have tested on Japan website pages covering a wide variety of topics
ranging from Japanese woodblock prints to Tokyo Disneyland. Results will
give you some idea of what to expect but try them for yourself as even
slight changes to page content and code placement will alter your results.