I use a lot of freemium services in my work and often the difference in value I get from the free option versus a paid upgrade is negligible enough that I don't have a compelling reason to pay.
With that said, one of the primary reasons I do choose the paid option (as I just did with bufferapp) is that I believe in the team behind the product and want to support them. When people and companies do things the right way, I am inclined to put my money behind them and I recommend others do as well.
How many apps that you thought were great went away because they couldn't sustain the business? We have been trained to think paying for apps and services is a drag and that free is better when the truth is it ain't...
What apps and services do you pay for that you don't necessarily have to and why?