Gold and Platinum are paid marketing slots.

We do what would be considered 'lightweight due diligence' in every ICO we list (i.e. we check project team Linkedin profiles, we read the white paper to get an overview of what the project is about and check that it has been created to a high standard. We ask questions to the team via e-mail sometimes with a few iterations). For the platinum, because it's a more prominent slot, we also did a few Skype calls with Daniel to make sure he looked like the pictures of him you can find online (he does).

That's what we have done, but note that Coinschedule is an informational website for marketing purposes, we simply list ICOs that are submitted to the website (if they pass our lightweight due diligence) and we make money by offering paid slots to ICO projects. Seeing a project listed there should not be considered investment advice of any sort. You need to perform your own due diligence and decide which projects to join.