Speaking strictly from a sales/distribution standpoint, 6-packs are an easier sell than 12-packs.
During my days as a liquor store manager, I was much more likely to stock and carry a product that sold in 6-packs, as it minimized my investment. I could try a 6-pack of the new product, and if it sold, it would be a stocked product. If it didn't it minimized the money I had sunk into the product. I'd say it could be easier to sell your finished product to a retail location or distributor in the 6-pack format.
We sell in bulk, 6-pack and 12-pack, dependant on customer needs.