There is a collection programming books titled "Effective X", for language X. From multiple publishers, IIRC, though I think it may have started with Addison Wesley.

The majority of those books with which I'm familiar have pretty good if not excellent reputations.

I would suggest that this documentation's title may be acknowledging this, and perhaps -- deliberately or not -- leveraging it.

EDIT: No, maybe it was indeed O'Reilly. E.g. Effective C and Effective C++.