Info on the sample banner advertisement
The advertisement banners you see on the site are only samples. They are there to demonstrate to you that in case you decide to do advertisement on your site, your own banner advertisement may look something like the sample advertisement banners.
The banner advertisement can be in the form of writing or pasting JavaScript or HTML or CSS code where you want the banner to appear. This is easy to manage from the administration side of the site.
Popularly site owners who want to do advertisement on their sites collect code snippets from the third party company for which they are doing the advertisement. They then place the code where they want the advertisement to show. Similarly, many widget areas are there in the site where you can paste/write the code to show the advertisement.
It is not a requirement to have knowledge of codes in order to show banner advertisement on your site. As long as you have collected the code snippet from the third party company, using the user-friendly administration interface of the site, all you may need to do is just paste the code where you want the advertisement to appear. Once you paste your code as advised, you may see fine advertisement banners like the sample advertisement banners you see on this site.
In short the banners you see on this site are samples for demonstration purpose showing that by using The FOJ application, a site owner has the opportunity to do neat advertisement on his site.