There are many ICO research group sites that focused on blockchain technology and digital currencies such as Bitcoin and Ethereum. Only few are unpaid or mandated to do any of their reviews and do not provide any promotional or advertising services and only rely on donations. Their content is based on their own research, analysis and personal opinion, and the projects that they choose to review are based on their discretion. So still, it's up for the investors whether to believe or trust this ICO review sites or not.