When we first got our land, we looked into Christmas tree farming. It was suggested back then to divide the area into 7-8 equal plots. Then plant seedlings on one plot, 1 year old trees on the next, 2 year olds on the 3rd and then seedlings on each open plot every year after that. Since it takes about 7 years to get a tree up to decent size, it'll take you about 5 years after 1st planting to even start thinking about a harvest. But then once you start harvesting, you'll have continuous crop from then on out due to planting a plot of seedlings every year.
Then you have to figure in time and labor to shear and shape every tree every year. Plus side-spraying for the first 4-5 years until the trees are tall enough to outcompete the weeds and grasses. Then worry about insect or disease that attacks any 1 particular species of trees, so you may want to mix up your planting of species so that you aren't wiped out entirely by a disease/insect species specific incident.
Then you have to have insurance for you-cut operations, maybe do some pre-cut trees, maybe decide if you just want to sell an entire plot to a pre-cut Christmas tree outfit (when's the last time you saw a Christmas tree lot? Those pretty much died 20 years ago).
Then if you do you-cut, you have to have the lot staffed at all times weekdays, your weekends are booked for 6 weeks before Christmas, you have to have parking, solid ground if it rains, decide if you'll allow people to drive into the fields or you'll take them out in wagons, road maintenance, insurance for car damages, people that cut trees then dump them in the field because they see a nicer one on the way out. Maybe a hot beverage stand and some snacks. Wreaths. Bows. Ribbons.
A bunch of bow saws to loan out that will get lost.
A tree shaker.
A tree bailer.
Someone to man those pieces of equipment.
Yes, I'm sure you could make some decent money off of an acre of Christmas trees, but you'll spend some decent money off of an acre of Christmas trees.
I think the only ones that are making decent money are the places that offer 'The Total Christmas Experience' with the wagons, tractors, horse drawn wagons, gift shops, Frazier Firs and other exotic species, etc.
With that said, we still go out and cut our own tree every year. Last year was the first we didn't due to unforeseen circumstances. We went to the you-cut place after getting off work early on the only evening we were going to have free for weeks, it stormed buckets, and was completely dark 2 hours before sunset. The tree family was waiting on the porch of their gift shop for us. It was pouring. The guy asked us what kind of tree we were looking for, he disappeared into the rain and dark, then reappeared in 10 minutes with a beautiful tree. Wife said "We'll take it!". Fastest Christmas Tree trip ever.