Content marketing is visual. Posts with photos do significantly better than a post without or with poor quality photos. As a social media marketer, I can't stress how important having a good visual aesthetic is for any business. This means that you are constantly in need of photos. The great thing is you don't need to shell out big bucks on stock photos. There are plenty of sites that I use all the time for great stock photos.
Here is a list of which sites I think are the best for stock photos right now: