Clicksor is one of the current leaders of the small publisher Adsense
competition. They have payouts upto a market leading 85% and unlike a
number of alternatives the cost per click bid values are high enough
that you can earn a decent income. Their terms and conditions suggest
that you should only place one copy of their code on a page but as long
as you only place a single pop-up or DHTML code on a page they seem
happy to let you place many context sensitive ad blocks on a single
site.
Clicksor also has a big advantage over a number of the lower ranked
alternatives on this site in that their ads are truly context sensitive.
Thus while you can provide keywords they have technology that will also
show ads targeted to the content of your site. This means your visitors
are exposed to ads of the same subject as they were searching for when
they reached your site and thus vastly increases the click thru ratio
and thus your sites earning potential. The context sensitive nature also
saves you the hassle of having to specify keywords for all of your
sites and decide in advance what people might be looking for.
Advertising types :
Inline Text Links. Text Banners Rich Media Banners Graphic Banners. Pop Under. Full Page Ads.
Clicksor is ideal for small blogs / websites trying to monetize their traffic, but i would keep it has a third option.