A lot of LWites (including you based on your mention of LoveSystems) seem to be interested in PUA, which is similar to NLP in that it contains a LOT of scammers and creepy people, but also has a group of genuinely useful and non-scammy people (eg Rob Judge and Mark Manson). I think our quest for scientific stringency should not ALWAYS get in the way of investigating cool new stuff. I'm sure NLP could be tested. If it's possible to prove eg the existence of synesthesia in a lab setting then it should be possible to prove the stuff NLP talks about. But I'll admit the lack of scientific founding is fishy.

Here's another book I'm reading, btw. It's about NLP concepts of mirroring and rapport: http://www.begin2dig.com/2010/04/90-seconds-or-less-to-bond-skills-of.html

In essence, mirroring is about finding out how the other person's mind is wired to think (ie visual, auditory or kinesthetic for instance) and adapting your communications to that. It's like initiating a handshake with a server and choosing a protocol that it supports, I guess.