Quote from: ArithmomanicVampire on December 16, 2017, 09:39:41 PM

I have the private keys to several outputs in the 0.01 0.1 BTC range. This kind of amount is quickly approaching dust level (https://bitcoinfees.earn.com/ currently recommends ~0.001 BTC for a standard transaction). Suppose I'm not at all in a hurry, what is the best strategy to avoid the outputs to become effectively unspendable in the future?

Combine them all in a single output?
- Since I'm not in a hurry, I could use a very small transaction fee, say one that gives the transaction a ~10 % chance of getting mined. If it doesn't get through, I can simply resend it.
- I read somewhere that transactions stay in the mempool for 72 hours. Is that correct?
Do nothing and just wait?
- The lightning network should make sending bitcoins cheaper. But that per se doesn't help in this case as the small outputs are still there at a fundamental level.
- However, if the lightning network reduces the number of actual bitcoin transactions, they should become cheaper.
- The transaction costs may not go up much higher because only holders of larger assets would be willing to pay the fees, leading to an equilibrium.
Something else?

You should combine them all together, and then try to have atleast 5sat/b, and try to get it confirmed by adding it into mining pool accelerators such as http://confirmtx.com.

Transactions usually stay in the mempool depending on how long you keep broadcasting them. If you don't stop broadcasting it, it won't disappear.