Gnosis did a very smart token sale. It did its homework and in December 2016, Chief Strategist Matt Liston released a blog titled Introducing the Gnosis Token Launch. This is where the concept of the Dutch auction was introduced. Keep in mind that this was five months before the actual ICO.
A Dutch auction is where a good (or service) is set at an artificially high price where demand is known or believed to be zero. At publicly known time intervals, the price ticks down in publicly known price values. The price continues to tick down until the first bid is received. At this point, the auction ends immediately and the bidder wins the goods at that price point. The advantage is that the buyer recognizes their fullest economic benefit from the sale because that is what they were willing to pay in the first place. It is also quick and simple to implement and understand and only one bid is required. There are not a million hands waving all over the place, for instance...