At first glance, these might seem like any old store points card, and in principle they are, but these offer something a little extra special every so often.
I get an email from Liberty Beauty about once a month telling me my points balance (usually not much), but the most exciting thing is hidden near the bottom of their email.
Marked 'rush to counter', they frequently offer you a chance to try a product from a brand for free. All you've got to do is go to the counter and show your email/loyalty card and get one before stocks run out.
From emails like this, I've previously managed to try out Hourglass' Script eyeliner and on Tuesday got my hands on Anne Semonin's Eye Express Radiance Ice Cubes (worth £44!).
You have to be quick (I'm talking within 24 hours normally), so it's really only good if you live in London, but if you do, why not sign up and get one; they're free after all...