I know complaints can be annoying but they're also valuable feedback. The point of any game site, after all, is to be fun. When people are complaining, it means they're not having fun. When enough people aren't having fun, it means that there might be an area of the site that can be improved. This is true regardless of whether the original complaints have merit per se.
What I mean is, sure, you can argue that people shouldn't be complaining about not getting free stuff that was as good as other people's free stuff. After all, it's all free stuff, right? But what the complains tell you is that, for whatever reason, people aren't finding the giveaway as fun as they could.
Look, basic psychology: people are unhappy when distributions are inequitable. If you parents give your brother a new car for Christmas and you a new DVD, you'd be unhappy, right? Even though, hey, free DVD? This even works with monkeys. I saw a great talk on this recently. If you have two capuchin monkeys and you give them both a slice of cucumber, they're both happy. If you give them both a grape, they're happy. If you give one a grape and the other a cucumber, the one that got the cucumber is one pissed-off monkey. (The talk included a video where the monkey who got the cucumber threw it away in disgust, whereupon the monkey who got the grape promptly snatched it up and ate it.)
I think the thing about giveaways is that when a few people get something incredibly valuable and most people get nothing, the people who get nothing are likely to be upset. It's the nature of humans and, in fact, of primates in general. You can tell us we should be happy to get cucumber until the cows come home, but we're still going to be jealous of the monkey who got the grape.
I think there are a few things that could be done to make the giveaways less like the cucumber-and-grape scenario. One, I think there should be an upper limit on how valuable the things that are given away are, and perhaps a lower limit as well. When in one moment of luck people can get an item worth more than I've ever made on the site, I find it discourages me from working to earn sP. I'd rather see a giveaway with more items of medium value (maybe tens of thousands up to a few millions) rather a giveaway with a few 100-million sP items and a ton of 100-sp junk. I think that this helps avoid the cucumber-and-grape scenario if everyone gets a chance to snag something good (even if they don't get the really really good stuff). I also think when the item values are less variable then the giveaway just becomes more fun. You get to pick out cool free things, rather than desperately refreshing hoping to hit it big.
Two, I think that new items should be added continuously over a protracted period of time (or maybe continuously over an hour or so, for several time windows throughout a 24 hour period to let all time zones participate) so that all the good stuff isn't gone within the first ten minutes of the giveaway.
