When blockchain developers need funds prior to ICO (Initial Coin Offering), they offer a crypto presale of the project's tokens. Usually priced low, if the project is successful, these tokens would later net the interested parties a hefty return on investment.
The difference between ICO and a presale is that the latter consists of tokens priced at a considerable discount with extra bonuses. This way, investors gain a direct stake in the blockchain project, with huge potential gains if they later decide to sell tokens when they appreciate due to the project's popularity. Moreover, such presale funds are often needed to fund the public ICO itself.
Because these crypto presale tokens are usually discounted, they represent a very attractive target for investors. Also dubbed as pre-ICO, they are a necessary tool in the blockchain space because there is no regulatory body to determine the potential worth of a project.
To bypass this problem, presale is effectively an ICO private sale, where investors take on the risk if the project doesn't pan out. Most commonly, crypto presales are generated by close associates, friends, family members, or so-called angel investors.
You can find such projects at the CryptoTotem aggregator under the pre-ICO listing. As you can tell, crypto presales are used to develop the very early stage of blockchain projects. Naturally, such an investment vehicle also offers a vector for scamming, which can turn both ways. Developers could take off with the funds without completing the project, leaving investors with worthless tokens.
Likewise, investors could leave developers dry by selling tokens immediately after the launch. This would deflate the token's price, giving the protocol a bad look and turning off other potential investors. Needless to say, this makes crypto presales highly speculative, as we can see from the example of Cofound.it.
Cofound.it had received funding from 1521 supporters. Its token presale completed in just 60 hours in June 2017, worth €12.6 million (56,565 ETH). As the project's name indicates, it was supposed to be a blockchain platform for funding other ICO projects as a decentralized alternative to Venture Capitalism. Unfortunately, the CEO Daniel Zakrisson shut it down and distributed the assets a year later due to "power had shifted to early professional investors and hype factories promoting ICOs to retail investors."