When it originally aired on December 4, 2010, the episode scored a preliminary 2.8 adults 18-49 rating, so the 2.3 for an "encore telecast" seems pretty good.
via NBC press note:
In late-night metered-market households Saturday night:
- An encore telecast of “Saturday Night Live" (4.0/10 in metered-market households), hosted by Robert De Niro with musical guest Diddy Dirty Money, dominated its time period. Versus the same night last year, the "SNL" rebroadcast is up 5 percent in metered-market households (4.0 vs. 3.8).
- In the 25 markets with Local People Meters, “Saturday Night Live” averaged a 2.3 rating, 9 share in adults 18-49, making it the #1 non-sports telecast of the night, ahead of all primetime entertainment programs on ABC, CBS, NBC and Fox.