 Headphones and earbuds are also expected to see major discounts. But in recent years, Prime Day has had to share the limelight with sales from other online retailers. Both Walmart and Target had kind of their rival sales a week earlier. A report from market research firm eMarketer finds that Amazon's share of online sales during this Prime Day will be smaller for the third year running. With TechTrends, I'm Mike Dabusky, ABC News.