NEW YORK -- CBS Entertainment chief Nina Tassler chuckled Wednesday when a reporter asked if she's prepared for the onslaught of mail from "Moonlight" fans upset about the show's cancellation.

"It had a very passionate fanbase, and that's a good thing," Tassler said. "We just had to make a lot of tough calls."

One of those calls was not renewing "Moonlight," the rookie drama about a vampire (Alex O'Loughlin) and his star-crossed relationship with a mortal woman (Sophia Myles). The show performed OK in its Friday home this season, averaging a shade under 7.5 million viewers per week. It was, however, the weakest performer in CBS' Friday lineup; "Ghost Whisperer" drew 8.7 million viewers and "Numb3rs" 9.1 million.

Tassler says the fact that "Jericho" failed to improve its ratings this year following a massive fan campaign to un-cancel it influenced the network's decision to some degree.

"It was a factor, obviously," she acknowledges. "But the nice thing [about 'Moonlight'] is that it did have a loyal fanbase. ... But it's hard to judge the actual numbers" of those who are actively trying to save the series.

"We had to make a very tough decision," she adds. "I loved that vampire -- what can I tell ya?"

Tassler also put the kibosh on a report that The CW is interested in picking up the show as part of its farmed-out Sunday schedule, which is being programmed by independent producer Media Rights Capital. "Probably not, no," was Tassler's response to a question about the rumored move.

The CW unveiled the titles of two comedies and two dramas for Sunday night at its upfront party Tuesday night; "Moonlight" wasn't among them.