Likely you won't have any issues with Canada border services, as you're continuing on to the USA. They'll do an immigration passport check and you'll be on your way.
The issue is going to be USA CBP at the US transborder preclearance area at YVR.
Again, you probably won't have an issue with US customs, but the items you're bringing in will raise red flags for US immigration. (Assuming you're not an American.)
Even with GE, if you're not an American citizen you will still have to answer the "where are you going what are you doing?" questions. Most Canadians heading to trades shows (I'm at one now) don't even travel with brochures, much less commercial samples.
The American border officers will be concerned that you are heading to the USA to 'work' and commercial samples are an indication of that.
If at all possible, and if budget permits it, I would ship everything via a courier to meet you at your destination in San Francisco. You should carry little more a few business cards (under 7).
Originally Posted by
Skatering
I would go ahead and use a Global Entry kiosk. There's usually a question about commercial goods. If there's not, you could either 1) Tick the question that most closely matches what you have or 2) Make a verbal declaration to the nearest CBP officer.
1) I would simply answer the questions on the machines truthfully.
2) I would answer the officers questions truthfully, but do not volunteer information. If s/he asks if you have commercial goods, answer truthfully if that's the case. If they do not ask, do not volunteer it.