When selecting a cloud-based data storage vendor, reviewing the vendor's compliance certifications is the most important factor. Vendors with recognized certifications demonstrate that they adhere to industry best practices and regulatory requirements. This instills confidence in their ability to protect sensitive data. Although reviewing testimonials may provide some insight into customer satisfaction and data center location can relate to data sovereignty issues, they are not as critical as ensuring the vendor follows compliance standards. Cost is also a factor but should not supersede security compliance considerations.