It's sad to say, Google updates do affect some back links, take
authentic chinese food recipes blog as an example, It stucked on #3 position, It should be on 1, I need to figure out what kind of back links getting weak,
Forum back links are easy to get traffic but difficult to affect ranking quickly,
Web 2.0 is testing, this should be very strong,
blog replies i think is weaker than before, but still works, If you can get a blogroll back link, that will be great.
Articles backlinks need some skills,...