Amazon’s four-day Prime Day ended Friday. Adobe estimates US online spending across all retailers during Prime Day promotions at $26.4 bln, slightly above its $26.3 bln projection and up 9.3% YoY from last July’s Prime Day. Discounts were similar to last year, with electronics and apparel deepest, average markdown about 24%. Consumer-research firm Numerator says average Amazon household spend over the four days through Friday 4pm local time was $143, down 8.3% YoY.