I took at least a dozen co-workers shooting during 2009-2010--each for his or her first time (okay, several had prior military experience, so were not strangers to shooting, but had not shot for five to twenty-plus years).
My new goal is one per month. This year so far I have taken three, and I took a fourth today. Unfortunately, the (indoor) range was closed for maintenance, so we will try again next week.
I have had several people come up to me at work and ask me about shooting, and I always invite them to go. I bring spare hearing and eye protection. We start with a safety briefing/firearms familiarization. We always start by shooting a .22 (I bring both an S&W M18 and a Ruger MkII and encourage them to try both). We only move on when the shooter is comfortable. Some will try a .38 or a 9mm, some may try a .357 or a .45. I always bring several centerfire revolvers/pistols. I bring the ammo, and generally pay the range fees.
I only have two rules (above and beyond the Four Rules). First, we will be safe. Second, we will have fun. We achieve both. How do I know?
At least five have already bought one or more handguns, and two more are in the "shopping" phase. One has become an NRA Life Member. Several are talking about getting their CHL.
Back to the original question. I guess my discretion is somewhat lacking.
But I am okay with that. Barack Obama may be the #1 Firearms Salesman of the Year, but I'm working hard to be #2.
ETA: I am more interested in creating more new responsible firearms owers (and perhaps CHL holders/NRA members) than I am about being discreet. All of life entails some measure of risk.
Oh, and I don't do social networking.