it's still going strong (and growing little by little)...

Makes sense! Without naming specific sites (I could list many): what are the possible reasons why a news site with a coupon project doesn't fit into the SRA? Guidelines say there mustn't be 'intent' to manipulate SERPs by leveraging their authority in areas far from the core. How is this evaluated?

There are also examples from other EU countries, like descuentos.lavanguardia.com, stern.de/gutscheine, and others. What makes them different from the penalized projects?