Overly sales driven messages can be ineffective for several reasons: 1. Subscriber Fatigue: Receiving constant sales pitches can overwhelm and annoy subscribers, leading to higher unsubscribe rates. 2. Lack of Value: Emails that focus solely on sales fail to provide value, which is crucial for maintaining subscriber interest and loyalty. 3. Trust Issues: Aggressive sales tactics can erode trust, making subscribers skeptical of your intentions and less likely to engage with your brand.