Out of the mouths of our Grandparents

We recently (like yesterday) got Vonage. Now, this is great in two ways. 1) We are more closely connected to our friends and family, as it is not an international call for us or them anymore, and 2) It is less expensive, because it is not an international call for us or them anymore. I emailed everyone our new phone number (Deleware area code, vice a Japanese country code, thank you very much!). However, I could not email my grandparents because, like many of our older generation, they do not have the internet (GASP!) and are just as happy without it (double GASP!).
What is funny, however, is that when I called my grandparents to give them our new Vonage-provided U.S. phone number, my grandmother thought it was a type of cell-phone service, and my grandpa had no clue what I was talking about. I explained to my grandparents, that no, it was NOT a cell-phone provided service, but a phone call over the internet. She got that. My grandpa, still didn't have a clue what I was talking about.