I would imagine that Google would view suspiciously a large number of links (even if built slowly over time) from two or three people as highly suspect.
Some of the automated approaches (e.g., Magic Submitter) allow you to create multiple profiles which MS will use to create blogs and other accounts as part of a link building strategy. They show as much in their instructional video.
Is this necessary? If so, how many identities are needed for how many links? If one just uses a single identity, will that detract or eliminate the benefits of the backlink building?
Thanks in advance!