In their method you make profile links on High PR websites. The only problem is your link will be a PR0 and really just worthless in the eyes of Google. You might even have to build backlinks to the backlinks you created with this method to get them indexed. I would focus on authentic high page rank backlinks that are on the high page rank page. If you have any other questions please let me know.
Angela and Paul are two guys who build links for their paid customer. The backlinks they will provide you is of high quality. They have started their business few years ago. Read more here: http://www.seoexplain.com/link-building/angela-and-pauls-backlinks-what-how-and-why.html
It is a list of web 2.0 sites that allow you to post links on them. The links used to work great, but no longer help in terms of seo whatsoever.
You can find more on angela paul's method here. But i dont think it is as useful as they say. http://www.seoexplain.com/link-building/angela-and-pauls-backlinks-what-how-and-why.html
Its a more spammy way of building backlinks. Go to forums create an account and drop your link on your profile. That is it.
SEO often splits opinion. A&P links have been seen to provide great results for some whilst others claim it achieved nothing. If you do test A&P links go slowly. It is better to add a few profile links occasionally, using different anchors etc. Do not buy hundreds in one go as Google may identify this as unusual for your sites normal pattern. I have never heard of A&P links doing damaged when built slowly but I have never claimed to be an SEO expert. In SEO slow and steady often wins the race.
I think its a piece of trash. It can increase your link could if you want to show case to your client about your backlink numbers, but may not be worthy to put much efforts on that. Lately Google is not even crawling those pages.