I wonder how difficult would it be to do this with cloud services, I mean to scrape voucher codes for free credit. For instance when Digital Ocean announces som

I wonder how difficult would it be to do this with cloud services, I mean to scrape voucher codes for free credit. For instance when Digital Ocean announces some promo and you can get 10 USD worth of credit. There are some sites that allegedly publish coupons, but I feel like a dummy only scrolling through those, it's full of ads and crap. What would be the proper channels to scrape for promo codes of the cloud providers? Twitter feeds, something else?