The next step is to review your data sources and quality, as they are the foundation of your segmentation and targeting efforts. You need to ensure that you have access to reliable and accurate data from various sources, such as web analytics platforms, CRM systems, surveys, social media, etc. You also need to check for any data gaps, errors, inconsistencies, or duplicates that could affect your analysis and decisions. For example, you could use tools like Google Analytics Data Studio, Google Tag Manager, or Google Optimize to verify and validate your data collection and integration.