I have never... EVER been able to find any working coupons on such websites for ANY website or company (not just Aegean), apart from promo codes for which the online shop, airline etc. already had special sections set up, like, for example, for the VISASUMMERXX25 in Aegean's case currently (where XX should be replaced with the country of origin, like UK, DE, NL, FR, IT, etc. etc.

So yes, all those other websites are just shamelessly click-baiting.