Fragrance and bubbles. Those are the two things I find people looking for in soap. Although visually interesting gets their attention, good smelling holds it...
Ditto on fragrance and bubbles. And if it looks good, too, I think you've got a winner.
That was my take on my sister's week where I had my sister's test 9 different bars and give me feedback.
That said, what one person thinks is a great fragrance, isn't necessarily what someone else will think is a great fragrance.
So, on fragrance, you have a big decision to make. Another thing I learned is that people like the idea of goat's milk (or GMP). Whether or not they can tell the difference if it's there or not, I don't know. But, Goat's Milk seems to have huge label appeal.
Funny story: I was at the Farmer's market with my son's SO a couple weeks ago. We stopped at a booth that was selling handmade CP soaps. The soaps had nothing showing what ingredients were in the soap so I asked. The young gal tending the booth (like early college probably who was not the soapmaker) pointed to one and said "well, this one is lavender." I told her I could smell the lavender, but I was wondering what other ingredients. She pointed to another and said "well, this one is goatmilk." It was a nice whitish color and I again told her I was wondering what other ingredients they had, like if they were all the same recipe. I told her I was curious about what oils were used. She seemed a little perplexed but then started digging around in a box behind her. She came up with a laminated poster that listed the 6-8 soaps she had, the oils, and the additives, like the EO and GM (although I think only one had GM). I looked at the poster and thanked her. I suggested she keep the poster next to the display, in case anyone else was curious.
When we left, my son's SO asked "why did they have all that oil?" I explained that soap is made mainly from oil (but could have lard, tallow, etc.), lye and water but that in the case of the GM soap, they may have swapped the water for GM or added GMP. She was very surprised. She thought the goatmilk soap was like coagulated goatmilk that has somehow hardened up- like cheese. On my cell phone, I pulled up soapcalc for her so that she could see a hypothetical recipe with the percentage of liquid vs. oil. She was very shocked that she was washing herself with oil. I did try to explain how she wasn't actually washing with oil, because the soap has gone through a process that turns it into soap. She, generally, seemed very disappointed by goatmilk soap. But, the funny thing is, this past spring when I had first started making CP soap, one of my sisters had a similar misconception and disappointment to learn that she wasn't washing with a bar of pure goatmilk.
So, I would say that if you want to impress, just think fragrance, bubbles, a good look, and an additive with label appeal.