When you pay for software/services upfront you know how much it is going to cost right away.
Great post from Ben Brooks on why he likes paying for things. I agree, I much prefer an honest transaction, where I am the customer, and I’m giving them money for goods or services. Of course, this is also a good place to draw a line between free and open source. If it’s free, you are not the customer, you are the product being sold. This applies to web services too. Gmail is free, but it is not open source.
In Ben’s theory, if Gmail were to be shut down, there’s nothing we could do about it. If it were open source, we could open up our own Gmail on our own servers. Furthermore, if Tweetie were open source, we could create a fork without the #dickbar. I think what Ben is really concerned with is the continuance of software that he enjoys, which is where I agree with him, and why I prefer my software to either be paid-for commercial versions or open source. Both models have a greater chance of sustainability than “free”.