My tier 1 has some well know Web 2.0 and profile links. For the web 2.0 I just put in one 500 word article are and index them. The profile links I drop a few words and a link. I can index these easily but I notice that after a while some of these then de-index. I can then usually index them again. My question is what is the easiest way to keep these links indexed. Should I add in more content to the web 2.0's.