In the past, marketers relied on focus groups and intuition to develop campaigns, but today, real-time and accurate data is crucial for high-performing marketing. A/B testing, also known as split testing, is an effective tool that helps optimize marketing campaigns. By adding CallRail, a call tracking solution, into the mix, marketers can take the data to the next level and gain insights into which variations lead to phone calls or offline conversions. Integrating CallRail with A/B testing tools like Optimizely, VWO, or Unbounce allows marketers to track call conversions and improve the overall effectiveness of their marketing strategies.