Are novelty fun runs stealing participants?

Here in Austin, TX we seem to have a 5k every weekend for all sorts of causes and reasons. I honestly didn't think we could add any more races into the year and then a couple years ago these novelty races started popping up and took off like crazy. I had friends covered in mud, color paint, glow sticks and zombie blood flooding my Facebook stream.

Image from http://thecolorrun.com/about/

This raised more than  few questions in my mind about the potential impact on non-profit P2P events and I haven't found too many articles written from this perspective so I thought I'd ask you, the Community:

• What have you experienced over the last few years?
• Do you feel these races are competing with non-profit fun runs/walks for time/space/participants?
• Or has it made our already fit community fitter and more likely to participant in more runs?
• Have you seen declines in participation that you attribute to the increase of popularity of these races?
• Have you altered your race feel to be more whimsical or fun since these types of races have grown?
• Have you had a harder time finding and booking locations for your runs because of the increased competition?
• Do you see novelty runs as competition or as a potential for partnership? (I did note that more than a few donate to charity)

I'm sure I'm not the only one who has had these questions, can you share your thoughts and experiences?