You cannot say it would be a bad thing in every situation. The people I am marketing to aren't new to the internet and they're not too young or terrible aged in a sense that they won't understand.
Having two sites would be creatively different. Not just two pages that look similar, but two complete opposite sites. Then maybe give them the opportunity to store a permanent cookie so they'll always see the one they prefer.
"Age is nothing more than an inaccurate number bestowed upon us at birth as just another means for others to judge and classify us"
sulfericacid