[hobs]

The article ended and then there was an advertisement in italics, I didn't read the article as an advertisement for their book as much as just a comprehensive slamming of NPS.

Which is a terrible metric that pretty much nobody should use.

[notimetorelax]

I agree with that, I think it's an interesting tactic to increase visibility of your product.

1. Create a strong worded post that attracts attention

2. Attach to this post your sales pitch.

[andrewingram]

I don't know if this tactic applies in this case. Jared Spool is a very well-known UX expert, he's also been ranting about NPS for ages. It feels more like the other way round, he wrote the post and attached a sales pitch, rather than (as you say) attaching a post to the sales pitch.