Running a crypto-only electronics shop, so rather than only asking, here are three things that cost me time to learn. Take what's useful.

1. The hard part of accepting bitcoin is not accepting bitcoin — it's reconciliation. A static receiving address plus a short human-readable order reference beat everything clever I tried. Ours are VV- plus six base36 characters, and the inbox matches that pattern in the subject or the body, because one of the two copy paths only ever lands it in the body. Matching a payment to an order stops being detective work the moment two people send similar amounts in the same hour.

2. Most "I underpaid" incidents are the network fee, not the buyer. Wallets and exchanges deduct the fee from the figure the buyer typed, so entering the order total sends slightly less than the order total. The fix that actually works is telling them to ignore the box they typed into and read the "recipient gets" line instead. Quoting in fiat and settling in coin also means stablecoins remove the arithmetic entirely, which is the version I point people to first.

3. Refund in the coin they paid with, back to the sending wallet, by default. It is easier to explain than any policy paragraph, and it closes an obvious social-engineering hole: someone who learns an order reference still cannot redirect the money to a fresh address, because a different address is only honoured inside the original email thread.

One free win I did not expect: keeping addresses in three incompatible formats (bc1…, 0x…, base58) means a buyer who picks the wrong chain family gets rejected by their own wallet before anything moves. That rejection is a safety net, not a bug. The one case nothing catches is an EVM address being valid on half a dozen L2s, so the withdrawal screen has to be chosen by network name rather than by coin.

What I am trying to improve is the front of the funnel — finding people who already hold coin and would rather spend it than sell it for a card payment. If you have run acquisition for a sats-accepting shop selling physical goods, what actually moved units, and what quietly wasted your time?