Betty White brought Saturday Night Live its highest ratings since last year's pesidential election as she co-hosted the late-night show and appeared in virtually all of its satirical sketches. The episode scored an 8.8 rating and a 21 share in preliminary Nielsen ratings. (Final figures, including the estimated number of viewers, is due on Thursday). The ratings were higher than those for any show -- on any network -- airing earlier in the evening during primetime, and they will likely turn out to be NBC's highest for the week. White's appearance was the culmination of a Facebook campaign that began after she was featured in a hilarious Snickers commercial during this year's Super Bowl (repeated during Saturday's SNL episode). In her monologue at the beginning of the show, White thanked her Facebook supporters, then added "When I first heard about the campaign to get me to host Saturday Night Live , I didn't know what Facebook was. And now that I do know what it is, I have to say it sounds like a huge waste of time." The SNL episode also brought together some of the long-running series' Golden Girls from this and previous seasons. (It was Mother's Day, after all.) Among them Tina Fey, Amy Poehler, Rachel Dratch, Maya Rudolph, Ana Gasteyer and Molly Shannon. It was the first time in memory that women dominated the show's cast. For the most part, critics gave the episode rave reviews. "White's rising star in the last year is a testament to the power of social media and a happy development in a pop culture that seems to be getting tired of all things pretty and perky," wrote Boston Herald TV critic Mark Perigard. "All it took to reinvigorate a 35-year-old comedy show was the presence of an 88-year-old woman," commented Dave Itzkoff in the New York Times. And Robert Lloyd summed up in the Los Angeles Times "It's Betty White's world now." But USA Today TV critic Robert Bianco was left unamused. "Think of it as another Facebook faux pax ," he wrote, adding "Saturday's overhyped NBC broadcast mostly served to explain why SNL seemed so reluctant to bring White on board. Clearly, they didn't know what to do with her."