L.E.D. lights were developed based on the principle that fish are attracted to light. It is the next step up from the glow in the dark counterparts.
I'll give a brief history on this.
Glowing lures were first presented around 1956 in the Great Lakes region. The notion that fish would go for it was ridiculed heavily. But, some folks tried the lures and continued to fish them with remarkable success.
As the years passed and decades ticked away, the concept became ever increasing with the invent of newer lures, different styles. By the mid 80's, nearly everyone had glowing lures in their tackle boxes. The short of it being it took about 30 years before they became mainstream.
Now, as those years went by, technology allowed us to learn more about marine life and discoveries made. It was found that there are a great many sealife that either flash or display light in one form or another. Most of these marine species live at great depths and nearly all are "bait" species.
As SpringFever pointed out, the use of L.E.D. lights is pointless on sunny days and shallower waters. Pirates Den Fishing has never advocated their use during these times or conditions.. unless you have money to waste.
But, when you are fishing in darker conditions, overcast days, night/early morning, stained waters or going down deep, the lights do help. L.E.D. produced light is rapidly absorbed by natural light, this is the plain truth. These lights should be used when fishing in excess of 90ft on sunny days and as shallow as 40ft on overcast or rainy days. Night fishing, of course, means the lights are visible in any depth. Using them can prove more productive, too, if the seabed is thick with ocean fauna as the light can provoke a strike as it flashes through the grass.
So, back to your question- "do they work": YES !! and No. Like anything else, there is a time to use them and a time to save them. There is a way to use them and a way not to use them..
Due to the west coast waters being as unstable as they are, not many folks go for night fishing- it is risky to say the least. On the southern end of the coast, the Gulf coast and along the southern Atlantic, many night fishers use the lights even when top water trolling with success. Of course, fishing styles are as varied as the fish themselves, but it clearly makes sense.
Pirates Den Fishing is the original L.E.D. fishing light in North America and each year, our sales have steadily increased and are offered by more and more retailers. There is a reason for this- they do work. I, personally, am an avid angler having fished all along the entire North American east, west and Gulf coastlines, the Great Lakes and from one to the other of the mighty Mississippi as well as Japan, China and Taiwan. Like everyone else, I have bought and tried far too many products that failed no matter how I used it. It is disappointing at best. We sell these products because I firmly believe in them.
We do not and will not stock any and everything. While I do enjoy making a buck here and there, I am not about to sell what does not work. Everything we sell has been tested and retested. Not just by myself or others working with me, but you guys- the ones that matter and offer an unbiased opinion. There are a few threads right here on this forum where I asked for volunteers to test concepts for us. And, this is not the only forum I post in-- it is one of about 280 and in each one I have different user names and ask those members to test items for their specific areas/species. No product has any identifying markings because I do not want bias brought into the test.
Ok, so let's discuss smaller lights. Yes, I am working on them. Like a mad scientist, I have spent hours at my work bench trying to build something smaller, lighter, more compact. And, I have managed to do so. But, there is a trade off-- in order to make it, the compromise is shorter lifespan. Cost is the next consideration-- it would not be much less than our current offerings. The reason being that component costs have gone up, shipping has gone up, taxes have gone up, fuel surcharges have gone up, labor has gone up and tooling costs for the molds. How many are willing to live with that? Would you be willing to pay almost as much for a smaller light even with a significantly less lifespan? I am talking about maybe 40 hours of life.