"I think it speaks to social media's "soft" connections, literally and as it relates to volume, plus (as in your first example), one of focus. On Twitter, ~80% of what I post is publishing-related, so the occasional personal tweet can seemingly come out of left field and likely be missed. A personal email to someone you have a relationship with is always going to be more effective, as long as it's used selectively. And for marketing in general, Godin's "permission marketing" is still one of the most relevant concepts people need to understand, and one of Amazon's major strengths. Email is far from dead."
- Guy LeCharles Gonzalez