Just played around "Create a HTML subscribe form"
I come to "Lists & Subscribers tester Grow your audience Create a subscribe form" and added the code (after 'get code") to my asp.net site but it is not working.
So my question is :
Do I need to pay that (account) first?
or it does not support ASP.net?
You won't need to pay anything for the form to work, so that's not the issue. The first thing to check is for form tags that wrap around your whole page - if you have the page content entirely enclosed in form tags, that will break our form if it's placed inside.
We've seen that a few times before. If that's your issue then you'll either want to use a subscribe button , link to a form on another page or place the form inside an iframe.
If you can't spot the problem, just let us know which URL you are working on and we can take a look for you.