How can small businesses measure the impact of hiring a freelancer?

[Btaliat]

There are some people that have seen small business owners that embark on freelancing as wasting of money. They believe that small business owners should rather focus on using other means that are cost-effective, like social media to get their businesses and services promoted rather than making use of freelancing services. What do you think about this? Do you really think that there is a profitable way of measuring impact of freelancing on small business?