[13rules]

To me an email like that doesn't tell me they are more interested to 'engage'

When it's an email like the one from this blog I actually do feel that they are looking to engage — even though I know the email itself wasn't sent personally.

I like the invitation to reply — I've done that several times with a random question or thought about the product / service. Knowing that the person on the other end expects and welcomes those kinds of random emails is helpful. Otherwise, I probably wouldn't send it — and I expect many others feel the same way, which is why these types of emails are seeing a lot of success.