I got my flu shot today, a relatively painless process (if you don't count the actual needle poke itself, which felt like a mild bee sting). I called ahead to my clinic to confirm that I could just walk into the Pharmacy without an appointment, which I then did. They collected my insurance information and since flu shots are rightly classified as preventive care under the Affordable Care Act (Obamacare), it was free. It was also Thimerasol (mercury) free, which I liked, even though there is no conclusive evidence that the trace amount of mercury in this vaccine preservative is harmful in any way.
I haven't a clue whether this year's flu shot will be effective, and for the most part neither do the epidemiologists at the CDC who helped design it. It's all a numbers game.
I am just really glad flu vaccines are free. Before Obamacare, you had to pay for them, even if you were insured or just went to Walgreens. That was never a big issue for me, but I can imagine there were a fair number of people who spent that $25 bucks or so on other more immediate needs, like say food.
A lot of the effectiveness of vaccines has to do with "herd immunity," a group level health effect whereby you don't have to vaccinate everyone, just enough people to prevent the spread of the flu virus. It's a statistics game that takes into account contagiousness and incubation period and chance of fluid exchange between people. If you are unvaccinated, herd immunity means there is far less chance you'll encounter an infected, contagious person and further propogate the virus. Even if you do get sick, you are unlikely to encounter another unvaccinated person to spread it to.
You are basically just improving the odds that the virus can't spread fast enough to infect unvaccinated people. Here's an explanatory video: https://youtu.be/rAGHXMq9ttw.