I agree. People love giveaways and it helps make a coin popular in the beginning, but that's only to dump and make an easy buck, doesn't help long term. Why I've always been a fan of PoW over PoS is it gives some cost/value to the coin you've got. Staggered marketplace deals have been one idea (of many) we are considering, for example the longer you hold, the higher the marketplace deal for that coin goes in a predetermined pattern before it returns to a more stable and sustainable level. Obviously this would promote a bubble, but it would also encourage speculation, holding, volume and more people buying to get into the deals. If the value then drops on people selling for deals, counterbalances are in place for the deal to begin the cycle again and promote a new round of buying, volume and speculation. People will hold for that next round or sell depending on their outlook. Of course this is in some ways considered manipulation, but if it's open and transparent marketplace deals then it's no different to any shop encouraging purchasing through promotion. We are also planning a long-term 'investment' coin that has a fixed minimum rate of purchase on the marketplace. This however will require more work, trust and capital to start with.
I'm one of those people who love giveaways, as being originally a guppy-sized trader (started with $38 btc), the giveaways gave me a stake... which now means I have grown into, umm... I guess a regular fish sized trader (15-20 btc)?
But I never view giveaways as something purely to dump, even from the beginning. If the devs support the coin and I think it has a future, I'd hold or more likely sell, and buy back in later. Yet very few (not sure any) of the current giveaway coins seem to have active devs nor anything especially unique about their coins. Unfortunately many can't even wait at all with giveaways, and it's like... gimme coins... sell coins... in one motion. I'm also biased towards POS, as I don't mine, but yeah, POW does give a cost/value to a coin. It always felt like an artificial value to me though. I remember that Air coin pricing itself based on miner rewards, and I always wondered who cares if a coin makes itself difficult to mine... that shouldn't really mean the coin itself it worth more than it should. However, many people may not think that same way (and especially not miners).
An idea I thought could work for Noble was a form of POS, but not in coins, but in marketplace discounts, which is more or less what you just suggested. I think I even mentioned the idea upon the noble forum once upon a time. Such as hold a coin for a month, you get an extra 1% discount tacked onto your account... another month, another 1%, and so on. Cap it at a certain amount, just so people actually buy something eventually. Yet I guess there is only so much of a discount you can offer before you'd go broke.