Both methods have advantages for the employee and employer with no clear favourite.
Percentage:
- for employee, the advantage is that you can make more money if you are prepared to put the work in and are good at your job; the disadvantage is that if the work is not there, you do not get paid much
- for the employer, the advantage is that its a good way to motivate the employee; they do not have to pay them if they are not generating revenue and bringing patients in; do not have to pay holiday pay etc; the disadvantage is that they could end up paying a huge amount of money (which is not bad as they will be making it); another disadvantage is motivating the employee to do things that are not directly related to patient care and generating revenue (theoretically they not paying for this); there is also the ethical risk of employees 'over-servicing' patients to generate income
Salary:
- the advantage to employee is that you get paid every week (probably less than on a %, as the employer is carrying the risk of a quiet time in business and not the employee); holiday pay and other benefits is also probably included; pay will generally be less than a % if you good at your job, BUT may be more than the % if you not good at your job; a fixed salary at least lets you know what you will get from week to week (and can budget accordingly), whereas a % will vary
- for the employer they have a fixed amount they know they have to pay; the disavantages is holiday entitlements have to be covered and a salary is not as motivating for an employee; they will probably have to pay less under a salary than a % as they taking the financial risk of quiet periods
As the end of the day, I see no definitive answer - it has to match the employers and employee profiles and also the "risk" either party is willing to take -- also keep in mind that the legal requirements of either situation will vary in different jurisdictions.
In my wifes clinic we pay a very low salary with a small % on top of that - its covers the advantages and disadvantages of both systems for both the employer and employee. The way its set up is that the salary + % means they can get a very good income if they are good at what they do and are motivated to put the work in. Its also means a new graduate has the potential to earn more than me

.... if they want to
