They are frank about also selling the data for research, it is not underhanded. It's even opt in...

For example, they talk about it on this page, which is linked from the about menu (so available with pretty small effort): https://www.23andme.com/research/

I expect lots of people also like that they get updates when information about new markers becomes available.

I trust them to opt me out, not at all. It's safer to just assume your data is being used, regardless, because it's free money to them. If/when they get caught selling data marked as Opted Out, they'll get a pittance fine, paid with other people's money and bonuses for making numbers that quarter.

You're welcome to trust them, but no I.

> They could have done the analysis and sent you a printed sheet.

Could they tho? The ancestry analysis itself is based on the data of other users in other parts of the world?

> Disallow collection of personal information

It's all about the money, always. So not gonna happen.

What about people who would want to donate their data to further the research?

They can enrol in studies at actual (non-profit so they don't benefit from selling data, probably public funded) research institutes.

> non-profit so they don't benefit from selling data

Non-profit in the US is a tax status. Many CEOs of non-profits enjoy multi-million dollar salaries and bonuses.