Yes, promo codes are tools for attracting new users. But they still give bonuses or discounts, right? So, if you are ready to invest, it’s stupid to refuse using codes as they increase ROI. Btw, as for CCG vs HashFlare, I know for sure that the second site has bonus programs (they are listed here: http://hashflarecode.com/ ) and what about the first one?
Sorry, it seems that the server is unavailable. Check the site, it may be broken or smth like this, don’t know. For all who have the same troubles as mine, here are an alternative, another cloud mining site with plenty of discounts/promo codes: http://ccgminingcode.com/ . CCG is pretty famous service, unlike the link from the topic starter.
Signatures for all release artifact archives are included in signatures-v5.5.0-382aa8f.tar. For instructions on using gpg to verify a release artifact, please visit the Verify Release Artifacts page on the Wiki.