Caulfield, who played reformed vengeance demon Anya, said Buffy would have been ripe for its own social media frenzy – if only it had existed between 1997 and 2003 when the show was on air.
"I think it would have been an even larger cultural phenomenon with the presence of media like that," she said.
"Just the power alone that would give the creators and the network to keep moving forward...it probably would have pushed past the 'cult' section."
Co-star Nicholas Brendon, who played everyman Xander, said the closest they got was checking internet fan forums after gathering at creator Joss Whedon's house to watch each episode got to air.
"We were very cloistered...we shot in Santa Monica, so it felt just like a family, like we were doing a high school play almost, just with cameras," he said.
"It was so special to see our hard work pay off. I miss that camaraderie, the family aspect of it."