It is good to be inspired, especially abroad, by giant (certainly industry-specific) newsletters, which are actually the basis of the entire (giant) business on similar login pages.
3. Quizzes, audits, measurements
As humans, we love to test, measure, compare.
We are just like that.
If you have even the slightest chance to provide any of this on the website, please do so.
Quiz: 10 SEO Questions That Will Reveal If You Have What It Takes to Rank #1 on Google
5 English expressions that 98% of Czechs say wrong, are you one of them?
Test: 3 primitive accounting questions that will reveal whether you have what it takes to make pakistan phone number data a living as an accountant.
You understand the principle…
You can show people the results and offer the option to send additional content to their email (correct answers, tips on how to improve to pass the test, etc.).
You can also be less “friendly” and if people want to know the result, they have to enter an email address to which you will send it to them.
You will get more emails, but at the cost of annoying a lot of people (I don't want to give an email and I wasted 3 minutes filling out something I won't know the result of) and a lot of the addresses won't be of very good quality.
Anyway, I highly recommend trying the quiz tactic. You'll be surprised at how many responses (leads) you can get.