My niece has applied 2 years ago. She was selected but she didn't manage to go through the interview. She also said it was rather difficult to prepare all the documents so they wouldn't decline them. They declined her photo twice and she had to use a green card photo maker later, also she had troubles with her financial documents, these papers needed to be approved according to their rules which took a lot of her time.
Basically she followed all the requirements from their website and prepared for the interview, there are tips for that, too. She wasn't really upset when she didn't make it, though.
Hope that was useful, Jenny!