So, went ahead and signed the pledge because I'll do my best to spend 10btc whenever I have 10btc. Though, the part the confuses me is the "only if 1000 people do the same." Eff that. I'm going to do it anyways. I'm not going to help the community only if everyone else is.
Good point on the "only if 1,000 people do the same" comment, otherwise you have something like what this JO did:
https://bitcointalk.org/index.php?topic=34016.msg434059#msg434059The 1,000 part is twofold. One is so that people sign up knowing that they are not in this alone. The other is because with more people using Bitcoins for purchases, the more prices will stabilize. If you just try to spend 10 Bitcoin on your own and find that the fluctuations are too much, then you might get discouraged and you will be more likely to not continue. But if enough people do it all at the same time, then prices will become more stable and it will grow as a currency from there.
I encourage people to spend on goods with or without the pledge, but I think 1000 people could make an impact. There are 500 people logged into this forum right now. We should be able to get 1000 people to actually do what Bitcoin is intended to do.