Most website designers would baulk at having to implement a design that tricks the user. Unfortunately, other website designers have no qualms with creating shady websites open a window with a fake "close" cross in the corner that a user may think will close the window but in fact takes them to another (shady) site.
Back in 2011, the EU (European Union) Consumer Rights Directive was agreed and became law in the UK in June 2014. If you've ever bought from Sportsdirect.com you may have noticed a mug or brochure appear in your basket. For this, you will need to pay an extra £1. It's quite likely that most people won't notice this and inadvertently buy it. Because it's only £1, most people won't complain and remain a victim of this trap.
In terms of usability and providing your website visitor with a good experience this is one sure fire way of creating negative associations with your brand.