By what standards?
By commercial market standards in the late 90's (starting in Nov 98) and until Sega called it quits. The system's launch in Japan was hindered by buggy and somewhat incomplete software and the situation didn't improve until summer of 99 there. Sales were extremely slow too despite being priced well.
Capcom even delayed RE CV hoping the user base would be high enough by release.
The US launch was good in comparison, but the momentum didn't accelerate enough for Sega. A pivotal point in the DC's life span was how bad piracy got with self booting games that didn't require any hardware mod's.