I've been reading Seth Godin's book, "Small is the New Big" and it has some really great insights for any business owner, including chiropractors.
In particular, I found this passage particular relevant to chiropractic:
If you are defining yourself and your business in terms of your competition, you are living in an echo chamber. Companies and organisations don't grow fast at the expense of existing competitors. They grow fast for reasons that have nothing to do with whether your service is 5% better or your product is a little more convenient.
There are two ways to grow: by stealing from the competition or by growing the market. The first path is slow and painful and difficult. The second path is where the magic of fast growth kicks in.
We see this all of the time in chiropractic: doctors are fighting over the same patients, rather than expanding the number of people who use chiropractic for their healthcare.