Much of the text does not show well with the background on the main page "Receive mindful SQL challenges to solve. Emails twice a week?" - and the next page, sign up page, a lot of the text is basically invisible.

I am interested in getting some sql problems to sort out, but not likely to sign up for a mailing list to get them

Maybe if you had a blog kind of thing showing some example of the problems, and some past answers and discussions of problems and solutions?

After a couple tutorials and a book I am eager to learn more and actually do some stuff, so the timing for this is right.