Cloud Mining Without Investment - The List of Cloud Mining Services That Offer Free Bonus for Just Signing Up (with scams alert)

This free cloud mining list will be updated from time to time. Last update: 2018/December/17.
Welcome to report SCAM's in the comment! Free cloud mining list since 2015.

The followings have been verified to pay (check the comments for payment status): EOBOT, Moon Faucets, DonaldCoin(Closed), Faucetminer(Closed), CetoBeto(Closed), FaucetGo(Closed), OXBTC, CloudMinerGame(Scam!), 25Mining(Scam!), Bitzfree, CLDMine(Scam!), TopMine(Scam!), myHASH(Scam!), Hash-Line(Scam!), XMine(Scam!), Multi-Coin (Scam!), Bit Lite(Scam!), Course Mining(Scam!), MineGate(Scam!), RUBMining(Scam!), OverHash(Scam!), MicroMining, MinerFarm, Cloud-Mine, MineCloud(Scam!), Contract-Miner, Elite Mining Club (Scam!), FreeBTCMine(Closing), bits2u
Tips: Use the free bonus to mine Dogecoin if possible as it usually has the lowest withdraw threshold.
Don't invest too much into suspect services! If you want to investment a large amount money into cloud mining, try more trusted services such as Genesis-Mining (use code hl6V5J to get discount of 3 % on all Hashpower packages. New: use code HappyBirthdayGM16 at checkout for 5% discount valid until April 12th at 23:59 GMT(Expired)), HashFlare (10% discount code for any HashFlare contract (valid until 1st of April): HF17BDAY10,Halloween discount! Use code HF17HLWN10ALL on the purchase page to get 10% off all contracts!), OXBTC.

Recomended

1. Bitzfree (Paying!)
Sign up bonus: 20 GH/s
Note: You can increase your GHs easily by hacking other user's and re-invest your mined Bitcoins.
Links: http://miscool.blogspot.com/2015/11/bitzfree-free-bitcoin-cloud-mining.html

2. EOBOT (Paying!)

Sign up bonus:
Note: You can claim at their faucet of about 2000 satoshis (or equivalent worth of GHs) with login bonus 1 DOGE everyday.
Links: http://miscool.blogspot.com/2015/12/eobot-cryptocurrency-mining-made-easy.html

3.MinerFarm (Warning! Withdraw Problem! Paying!)

Sign up bonus: 100 GH/s
Note: This is a virtual mining game - you're not doing real mining but can withdraw real Bitcoin.

4. Moon Faucets (Paying!):
Note: Not cloud mining but faucet sites that you can claim when you want. Your unclaimed satoshi increases more slowly as time goes on.
MoonBitcoin

MoonLitcoin

MoonDogecoin

5. Faucetminer (Closed)

Sign up bonus: 1+ KH/s every 45 minutes.
Note: Another virtual mining game that can mine Dogecoin. Mininum withdraw: 10 DOGE.
Note: After refunded its users, this nice service closed on 25/July/2016.

7. DonaldCoin (Site is Down)

Note: Another popular and reliable free Bitcoin generator game with no minimum and instant payout to FaucetBox.

8. CetoBeto (Paying!Site is for sale.Site closed. Site is back!Closed!)

Note: The new DonaldCoin, free Bitcoin generator game with no minimum and instant payout to FaucetBox.

9. FaucetGo (Paying! Site is Down!)

10. FreeBTCMine (Paying! Closing)

Others

The following are some scam like cloud mining sites with sign up bonus, not recommended to invest unless you trust them. Be warned that many cloud mining services are just Ponzi schemes, for example, cloudminr.io (Read the story here). They all offer sign up bonus but have a high threshold for withdraw and even require deposit before withdraw. Anyway, you can do the mining before/without investment.
You can check the sites below at http://www.badbitcoin.org/thebadlist/index.htm (which comments/lists most of the below sites as scam sites) for scam advises/reviews, and check the paying status at http://www.cmmonitor.com/ and http://cryptomonitor.net/.

7. CryptominingFarm

Sign up bonus: 50 GH/s
Note: Bonus Hashrate is for 15 Years. You need to purchase minimum 20 GH/s before you can withdrawal.

15. OXBTC (Limited time offer! Expiry date: 2016/March/6th20th) Expired.Extended. Expired. (Paying!)

Sign up bonus: 1 GH/s to 1000 GH/s (random)
Note: Bonus is only valid for the first month on signing up (one-month contract).

23. RUBMining (Paying!) SCAM!
Sign up bonus: 1 GH/s

Note: Russian site, use google translate. Need a Payeer address to sign up.

87. bits2u (Paying!)

Sign up bonus: 30 2uhash

96. MicroMining (Paying!)
Sign up bonus: 20000 Satoshi
Note: Need to install their mining software.

113. Contract-Miner (Paying!)

Sign up bonus: Faucet (1 MH/s for every 30 minutes)
Note: Can withdraw through Xapo or FaucetHub, so it has no minimum withdraw threshold. You should claim your earning (Home-> Click "Finalize your contract (Get Paid)" button every 5 minutes as a beginner).

More unverified services:
http://digitalcoin.tk/freemining.html

Confirmed Scam Sites
http://miscool.blogspot.com/2016/08/confirmed-scam-cloud-mining-services.html