I think that's an important point here. The amount of advertising and promotion available to Tera and Jenna will not be equaled in these days of porn's budgets. You don't see big posters and display pieces of porn chicks anymore, do you? (@Fartz)
I also think that's a valid point about performance. Those girls were marketable because of their model looks on box covers and display items. I don't think they were launched into stardom because of their on-screen tactics as much as their photogenecy.(is that a word)