I tried using adsense link units on my blog, but I’m not impressed with the performance. I’m not allowed to tell exact numbers by terms and conditions, but it is less than usual adsense ad blocks. There could be several reasons.
Maybe I used it in a wrong way. Many people suggest embedding the link units in such way so they look like website navigation. I completely disagree with that, because it looks like an attempt to confuse people. Even if people click such links, they will not click the advertisement on the next page. And link units require at least 2 clicks to bring some cents for the blogger.
I don’t like link units because the advertisements look strange. Ads by Google followed by some keywords. For example: "Ads by Google Cameras Photos Software". It doesn’t tell anything to your visitor. Usual blocks are provided with a short description. People at least know what they can expect when they click on a link.
I’m not impressed by link units. But maybe it will work on your website, nobody knows for sure. I tried link units for 2 months to see how it performs. Maybe you should do the same way: try link units and watch how it performs in your adsense account. If it brings you money, you are one of those for whom it was developed. Good look and good profits for you!
P.S. Anyway adsense is a great system to work with.