If I say the same thing to my relatives, no matter where they live, I get the same blank stares.
I personally think it's not "where" but "who".
I try to use very common analogies and to speak as simply and directly as possible. I usually just explain the selling proposition and/or business model of the startup without any additional information about "how we do it" or "in what industry" or "who our competitors are," etc. If they want more details, they can ask.
I've ended up with a few stock answers I use for every one of my startups. I usually just state the problem, and my solution to that problem, in layman's terms. That usually gets the best response. People usually start asking more specific questions, and we go from there. I try to explain what my startup does, and to convey my passion for the business without sounding too much like a pushy salesman or a nut ;-) If the startup is profitable, I add that tidbit.
I actually went from getting blank stares to getting new business and referrals. A simple, clear answer about the benefits your business offers can literally turn people into customers on the spot...or at least promoters of you and your ideas. Genuine enthusiasm and passion is memorable, and people are drawn to it.