Many of the patients who walk through your doors have expectations that are set by previous patients. Often those patients setting expectations are not yours. Some are benign, some are positive, a few are downright nasty.
As an example, here are some posts from Well Past 50, a site for women.
Patients have access to more of this information and there will be a time in the not to distant future where your practice will be listed with patient feedback and ratings from your patients posted on the site. (If you've purchased on Ebay you'll know how possessive buyers and sellers are of their feedback rating.)
These types of systems produce negative reviews out of proportion since it's motivated consumers that go to the effort of praising or trashing your practice. But you'll still have to deal with it.
Patients have more information now than they've every had and it's changing the way they are able to research and evaluate you. How will you fare when all of your patients can intereact with each other without you?