Short answers, pulled from the story.
Japan received the first Dreamcast units on the 27th of November 1998 at a price of ¥24,500. Manufacturing failures prevented Sega from meeting shipping goals due to high failure rates in PowerVR chipset production.
Sony announced the PlayStation 2 on the 2nd of March 1999 which changed all prospects for the Dreamcast. US sales began declining as early as January 2000 despite having exceeded 1.5 million units by year-end 1999.
One group led by Hideki Sato chose the Hitachi SH-4 processor paired with NEC's PowerVR2 graphics chip. Sega management ultimately sided with Sato's configuration despite objections from IBM's Tatsuo Yamamoto.
Nine point thirteen million Dreamcast units were sold worldwide across its brief lifespan. The system was discontinued on the 31st of January 2001 after March 31 following three consecutive annual losses.
North America launched on the 9th of September 1999 with nineteen games including Sonic Adventure and Soulcalibur. Sega set a record selling over 225,132 units in twenty-four hours earning $16.8 million.