"Bird Seed analysis" This Bird Seed was bought from a National Discount Store for about twenty-four cents a pound. The bag did not allow a view of the contents, which we separated above. 1 pound (4 Cups) was measured and sifted to remove dust and debris; this yielded about one Tablespoon, as shown. Then the resulting "seeds" were sifted again to yield Millet-sized seeds. That produced about 1 Cup of the "good stuff". The balance was mostly Filler which Song Birds often scratch out of the Feeder to gain access to the preferable seeds. This Filler was mostly Milo. The remainder was precious little Sunflower Seed, Corn cob, Corn, cracked Corn, and wheat. The latter three tend to attract "English Sparrows" which is the last thing you want near your Bluebird domain. So roughly 1/4 of the Seed Mix was useful to most Song birds. That means it cost about 24 cents for 4 ounces or 96 cents a pound. The irony of it is that the local Farm Center sells bulk Millet for 79 cents a pound, which is all choice seed and costs 17 cents a pound less than the "cheap" Mix. So the bottom line is that "you usually get what you pay for". And unless you enjoy paying  20% more for filler mixes, or making 4 times as many trips to fill the Feeders, it may be worth your while to seek out a store that sells bulk Bird Seed. Or buy plain packaged Millet or Sunflower Seeds which will keep most of your Song Birds happy. If you're caught in a pinch and must buy that mixed stuff, buy transparent bags which display the contents. Then look for bags that are high on Millet and Sunflower Seeds. This ratio varies among manufacturers, and even among batches of the same manufacturer. To cut your Sunflower Seed bill by 75%, go HERE. It's best to put different seeds in different Feeders. Then Birds will not scratch out perfectly good seeds to find their favorite morsel. Locate Feeders where there is escape from Hawks, that will be attracted to the "Bird Buffet" which you create. Three dedicated Feeders for Sunflower Seeds, Millet, and Thistle Seeds, plus a Suet Feeder and heated Bird Bath will ensure the health of Song Birds overwintering in your back yard. A fifth very useful Feeder for Egg Shells will help maintain their Calcium level. Just bake Egg shells for 15 minutes at 400 F. Then crush them finely. Put some in a Feeder, and more on the ground. If you start feeding all year long,  you should never stop.  You will be feeding youngsters that may not get the benefit of  being taught to forage natural sources by their parents. Your Bird Feeder is the only food source they will know. A better plan may be to fill the Feeders during the winter months until Spring nesting begins. Then quit during the summer months when Nature's pantry is full. This will allow the young Birds to learn a valuable foraging lesson, and not concentrate them in the area of the Feeder, which may make their inexperience an easy mark for prowling Cats and Hawks.