bitcoin microtransaction spamOne of the newest advertisement method for Bitcoin companies is to send out free bitcoins to Bitcoin addresses, including those that belong to Bitcoin websites. It seems great; who doesn’t love free money, right? However, it’s been causing some problems for websites that require bitcoin deposits. See, these sites require confirmations on deposits. The bitcoin microtransaction advertisements generally don’t confirm, either because the advertiser sends too little, or they aren’t including the transaction fee.

One website in particular that’s having problems with these microtransactions is Bitcoin website Coin-Sweeper reached out to me and explained that the spam microtransactions are hurting their website. I asked them some questions about these issues.

Also read: A Solution for Trustless Bitcoin Microtransactions Is Here

Bitcoin Websites and Wallets Face Unique Spam

What is Coin-Sweeper?

Coin-Sweeper is a Bitcoin based game of luck and chance. Find as many coins as you can without clicking on a bomb and watch your reward grow!

The recent bitcoin microtransaction spam has been causing some issues for Coin-Sweeper recently, correct? Could you explain what problems they’re causing?

Coin-Sweeper, like many games, relies on Bitcoin for receiving and sending our payments from players. When receiving Bitcoin payments, a website like Coin-Sweeper has a number of choices:

• provide the funds into their account only after it receives X confirmations (commonly 1 confirmation or 3)

• provide the funds into their account immediately when it appears on the network, but only allow them to withdraw following the funds receiving X confirmations (commonly 3 confirmations or 6)

The problem is that many of the Spam transactions that appear on the network are going into our deposit addresses. Because they are so tiny (0.00000001 BTC in most cases) and they often fail to confirm it effectively stops the customers from being able to withdraw their winnings! Our system auto-credits the spam transactions to their balances but we have had a surge in customer support from valid customers who want to withdraw their winnings but they can’t because of this non-confirming transaction.

This problem is further compounded by people posting their Coin-Sweeper deposit addresses to the Bitcointalk forums when we run promotions. It seems that whatever mechanism the spammers are using seems to find the addresses on public websites like that and target those addresses with the transaction spam :(

What are you doing to solve this problem? Do you have a long-term plan in mind?

At the moment our short term solution has been to block the 0.00000001 BTC payments. But this isn’t a long-term solution as whether it’s 1 satoshi or 2 – the cost is still tiny to the spammers. Then each day we manually review all the blocked payments to make sure legit deposits are transferred into player balances. Down the track we can make our system do this, but it’s against the spirit of the Bitcoin network.

A screenshot of showing a bitcoin transaction. One Bitcoin address sent 0.00001 bitcoins to hundreds of Bitcoin addresses.
One of many spam microtransactions


The main reason why a transaction wouldn’t confirm is because a transaction fee (usually .0001 btc) was not included in the transaction. This means that miners won’t confirm the transaction because they have no incentive to do so.

Most of the time, the issues that the spam microtransactions cause aren’t too big of a problem for the sites; they can usually still function. However, they’re causing unneeded issues. Sites requiring deposits, such as Coin-Sweeper, will need to find a workaround to this issue, as it’s likely that these spam transactions won’t stop for quite a bit of time.

What do you think about the spam microtransactions hurting deposit websites? Comment below!

Minor edits were made to the interview for clarity. Transaction screenshot from Other images from Shutterstock.