A rather small amount, but yes. The are many reasons why I would do this:
1) It incentivizes the programmer to focus more on the actual projects (I don't want a programmer who has several other projects and just works for this project 2hours a day)
2) I want to demonstrate that this is a serious project. Obviously, it needs time until one can trust each other.
Yet, how does a developer know that I don't have other independent programmers developing exactly the same website and from those I just choose the best one? Paying a developer a certain amount of money decresaes this risks and facilitates the progress of building up trust.
There might be ppl who disagree with me but this is the way I see it.