Link Vault
Link Vault is an advertising network that a lot of SEOs use very successfully to increase their rankings. To do this, you have to register in the system with a good site that you get a lot of “Vaultage” for (Vaultage is the internal currency), and then create some “Links”. There are some minor disadvantages, such as a flawed controls system and absece of support for Unicode characters, but on the overall, it is a rather good network which I use a lot myself. Read more about Link-Vault (sometimes called LV) here.
If you need support for Unicode characters, there is another somewhat smaller network called StaticAds.
