Pictures I have seen show it more often on the right but closer than 8 inches more like 4 or 5. How about asking the fabricator where they see it most commonly placed with that type of sink and faucet set up?

There isn't any set rule. Put it where it works best for you.

I have mine in the right corner of my sink. That is that spot that feels most natural for me to reach for the soap. Having it on the left would have been awkward. Work at your sink and think about what feels most natural and put the soap dispenser there. How far from the faucet depends on the size of your sink.

To the right is the only good location since it has to go on the right side of the faucet as there is very little cabinet left to mount on the right side of the faucet due to the larger size sink as per the drawing in the link. .

I am right handed and hold the sponge in my right hand. My soap dispenser is to the right of the faucet and operates one-handed (thumb pressing down while I am holding the sponge in hand). I think 8" is too far.

More important to me than the horizontal distance was the spout reach and mounting it as close to the edge of the undermount sink as the fabricator could safely do. I ensured that the spout was long enough to squirt directly in a pan in the sink under it but short enough that the soap landed in the sponge in my one-handed use.

Thanks for everyone reply, I was hoping on relying on the installers expertize but was told by the fabricators that the home owners make the decision.

I totally agree Trebruchet, unfortunately, she left the decision up to me just before she left for her nigh course. Then showered and fell asleep when she came home as it was a long day for her.

I think I'll place it about 6" to the left of the faucet and hope she buy off on it, if she doesn't then I have some explaining to do.

The installers' should be here in less than an hour.

Are you guys left handed?? If not, I really think it should go on the right.

We just did this on Monday - our sink is a 30" single bowl and I have the faucet in the center, and the center of the soap dispenser is 10" to the right. Our installer said 8-10 was typical, but that it was 100% up to me. There really is no right answer, but as a right handed person, it definitely made sense to put it to the right of the faucet for me.

Both of my soap dispensers are left of faucet. Love them. No issue for this right hander. It will be fine.

Thanks for all the replies:

In conclusion the single hole faucet was placed in the center of the two sinks. The soap dispenser was placed in the center of the smaller sink which is 8" to the left of the faucet.

"I totally agree Trebruchet, unfortunately, she left the decision up to me just before she left for her nigh course. Then showered and fell asleep when she came home as it was a long day for her.
I think I'll place it about 6" to the left of the faucet and hope she buy off on it, if she doesn't then I have some explaining to do.

The installers' should be here in less than an hour."

No way would I drill that hole. Uh-uh. Nada. Nine. Nyet.

I drilled four faucet holes today. I put tape where the holes were to go and after the wife gave the okay, I photographed the tape in place then drilled. I would fake a heart attack to avoid picking a faucet hole. You really like to live dangerously.

I hear ya Trebruchet, laying out, and or drilling the holes aren't a problem when you're building the cabinets and doing the whole install yourself. I'm just glad I didn't have to drill out the holes as I didn't have the right size bit, besides, I gave them the location by way of finger pointing and they laid out the exact location.

As for the wife, we've been together for a long time, she's pretty flexable which is why she left it up to me.