What's up with MorningSave and signing in via Facebook?

lljk thought this was worth mentioning said

I was checking out Meh’s little cousin earlier and I noticed that at the top of the page, it recommends signing in with Facebook “to shop our exclusive offers.” Is this saying that there’s exclusive deals for those who link their Mediocre accounts with Facebook (sorta like how Woot has app-exclusive deals now), or is a Facebook sign-in just the easiest way to entice MorningSave’s target demographic into joining?