It has been said by many indie developers many times that purchasing games through key resellers is objectively more harmful for the developers than piracy entirely.

Key resellers tend to buy keys in bulk using credit cards. When the bank reports the card stolen, steam issues refunds. The developer of the game is responsible for these charge backs, not the storefront.

Basically, if you buy games from key resellers not only are you not giving developers money that they deserve, but you're literally taking it out of their pockets. Do not buy from key resellers, pirate instead.

Source via BBC News

G2A sells sketchy stolen keys, so does Kinguin. I've never had an issue buying from them, but plenty of other people have.

There are plenty of reputable sites though. When I'm looking for a game on sale, I go to IsThereAnyDeal.com and all the sites they list are legit.

As a small game dev, I can tell you that I get a lot of emails from people impersonating content creators requesting keys for "review." They then turn around and sell those keys on sites like Kinguin to make a quick buck. If you buy from key reseller sites, that's who you are supporting. Developers don't see a cent.

No, they are not legit.

Sometimes the keys they sell work, sometimes they don't, and sometimes they start out working but later get revoked. But more importantly...

They are even worse for the developers than pirating the games:

• https://www.bbc.com/news/technology-48908726
• https://www.digitaltrends.com/gaming/g2a-controversy-indie-game-developers-calling-out-illegal-key-resellers/
• https://factorio.com/blog/post/fff-303

It is better to wait for a Steam/GOG/Humble sale. Price tracking sites like this one can be helpful:

https://isthereanydeal.com/

Some are legit, some are scams.

As a rule of thumb, of it is featured in isthereanydeal.com , then they're safe

I've only ever used Humble Bundle to buy steam games not on steam itself. I haven't had a single steam key issue in the 13 odd-years that they've been around. ¯⁠\⁠_⁠(⁠ツ⁠)⁠_⁠/⁠¯

Gamedevs would prefer that one pirate the game outright than use shady key resellers.

g2a and similar websites are grey market websites. That means they're not literally illegal, but most of their keys are usually gotten illegally. Sometimes (it's rare, but it happens) people buy keys and they get revoked later if Steam confirms it was stolen. I wouldn't use them at all if you care about giving the developers their money, you might as well pirate it.

Meanwhile there are legit websites like Fanatical that do sell cheap mystery keys. Most of them are shovelware they're trying to get rid of, don't bother.

Most are scams, but there are reputable ones, like Humble Bundle and Fanatical.

Keep in mind that even if some are scams, they might appear to work at first. The problem is that the key you get may be marked as stolen or purchased with a stolen credit card/etc, and then your key becomes invalid even if you've already redeemed it.

Mystery packs are always just a scam to get rid of worthless keys by an illusive promise of possibly getting a good game

I've used eneba quite a bit. Even for MMOs. Never an issue. If someone knows it's a bad site, please comment. G2A seems to be the devil.

I sell my Humble Bunlde choice keys - not everything is stolen. It's my thing, I bought it, I'm entitled to selling it and someone else is entitled to buying it.

I've never had any issue with CDKeys, and they seem legit. Unlike G2A they're not a marketplace for shady resellers.

Often times g2a keys are purchased with stolen credit cards or acquired through other sketchy means and the game risks becoming invalid days or weeks after purchase. Had it happen to a friend a while back with Civilization 5.

Made severall purchases on G2A and Kinguin and never had a problem. I only buy old games though and only from resellers with a lot of reviews.

Stopped with G2A however when they asked me to upload an ID.