[gwern]

To update:

My message idn't make it in the first time and 21co notified me it has been canceled:

> Thanks for using 21 to contact Marc Andreessen and donate to Black Girls Code. Demand for Marc's time was extremely high and it was not feasible to respond to your message in 48 hours. As such, your credit card has not been charged. Marc still wants to hear from you though, so we encourage you to resubmit your message at 21.co/pmarca! The new estimated response time is one week given the high demand. We are working on adding code to dynamically update wait times in the presence of surges of demand, but in the interim we want to make sure you have a good experience. Thanks again for using 21 and supporting Black Girls Code!

I decided to try submitting again (I'm still curious and at least the price didn't increase).

I also mentioned my comments to 21.co. To summarize their response:

1. PNG: should be supported, they don't know why it didn't work 2. they'll check that the emails arrive in an actionable order 3. it's a flat 10%; it is to cover payment processing (so the user may be donating to charity but they're not) 4. performance is a known issue 5. you are not allowed to deposit Bitcoin, they have to be earned via the site; deposits may or may not be available in the future. Verification for withdrawals are required because of fear of abuse. 6. the responses are supposed to be private/confidential (I guess Horowitz simply doesn't mind or know about that one being passed around). So should I get an Andreessen response, I guess I will confine my comment to whether it was a good response or not and whether it might be worth the money.

(I don't entirely agree with some of the reasons.)

[gwern]

Got a reply this morning, 98 words. I think it was a good reply - it was mostly what I was thinking but it's valuable knowing that someone like Andreessen, who may know many secret things and has seen many tech sigmoids come and go, takes a similar view of things.