I handed out two more 25mBTC tips this weekend: the first at an IHOP (
https://blockchain.info/address/1L22MWVzmGEf36SHLPnZjZ6C1wZxVMzFaW) and the second at a jazz club in Vancouver (
https://blockchain.info/address/1Mn2PSAMP4aDrKSsSLkECAHTCSjW1Nzy2B) (see OP for more details).
Thanks everyone for your additional thoughtful comments. I’ll address a few below:
You should attach a leaflet with information / links to resources to increase the chance of adoption.
Just looking at the paper wallets I would assume 90%+ of people would be too confused to bother trying to figure it out for $20. I know if I handed this to my mom or dad they'd have no idea what to do, and if I gave it to my girlfriend she wouldn't bother to figure it out either.
I don’t think we necessarily want to
maximize the rate at which people sweep these funds. Of course I
could make each paper tip $100 and help everyone download the Blockchain.info app to their phone, and then sweep these funds to a private address for them. If I hired a handsome guy to push for this with a charming smile, then I’m sure we’d have close to a 100% sweep rate. But I think making it “too easy” or offering “personalized help” would be counter-productive to this experiment because:
(1) the funds allocated for this experiment would be drained much quicker, so less paper wallets would be given out in total,
(2) the “adoption rate” I calculate would be biased based on how much the server likes me (it would lose its meaning),
(3) like Carlton Banks mentioned in regards to not claiming the funds within 10 days, this "emotionally charged story will spread the general sense of 'get on board, train's leaving with or without you.'"
Instead of pushing bitcoin on the participants, I want to be very neutral and simply place these paper tips along with the cash tip on the table as I leave. If the server uses it, then maybe we’ve created a new bitcoin adopter. If the server doesn’t use it, then I get the funds back to give to someone else and perhaps we still triggered a conversation about bitcoin. Win-win I think. Also, by being neutral like this, the results of this experiment
over time will also be meaningful. If I can continue this experiment into this summer, it will be very interesting if we can measure a statistically-significant change in the adoption rate over time.
That being said, I may be willing to modify the note that I wrote on the backside of each wallet (refer to the figure in the OP). I debated about adding details like "download a Blockchain.info wallet app for your smart phone," "spend your coins at Gyft," or "gamble your funds away at just-dice.com" but I decided to simply leave a single link to bitcoin.org. This may or may not have been the best decision.
You can pay less fees on your tx btw, a fifth of that is enough, assuming you don't do this intentionally.
I used my Blockchain.info app on my iPhone and there’s no way to control the fees (unlike the blockchain.info web-wallet). Unfortunately, due to Apple’s restrictive bitcoin policies, Piuk does not want to update the app to make this much needed improvement, as he is worried about it getting pulled from the App Store upon a re-review.