Don't see why it wouldn't be any different than promoting most anything. Promotion can vary slightly, but still promotion.
I agree, PPC can be price and it can be very easy to lose all you money. You have to have the cash to test and find those winning campaigns. But it can be the fastest way to drive traffic. And if you target, say specific models, if it has search volume, that might not be too expensive and "should" be better conversions.
As already mentioned, Visual products like unique cell phone cases for example might do well on pinterest.
Reviews are going to come in as they come in, don't know how you can make them come in. Sure there are places you can buy reviews, but that can be risky.