SushiSwap published a blog post on September 9, 2020 that acknowledged Uniswap's "elegant design" and said that it intended to enhance the design with community governance features that would both reward participants but also award them voting rights through the issuance of SUSHI tokens. SushiSwap copied Uniswap's computer code, reduced the fee payable to "liquidity providers," and made up the difference with SUSHI that would be paid to SUSHI holders. Ninety percent of each distribution of SUSHI was to be set aside in a development fund.
With virtually identical software and financial model plus the addition of tradable governance token rewards, SushiSwap depended on liquidity providers on Uniswap to move their liquidity pools off Uniswap and onto SushiSwap. As the platform's September 9 blog post said, "To start providing liquidity and earning SUSHI tokens, anyone holding Uniswap LP tokens can stake those LP tokens into the corresponding initial list of pools."
Upon launch, $830 million of assets were moved from Uniswap onto SushiSwap. Early transfers in "The Liquidity Migration" were incentivized with a SUSHI pay out ten times larger than normal. The amount staked to SushiSwap quickly rose to $1.68 billion of Uniswap tokens. 
The original pools available for participation were:
Chef Nomi's shenanigans
Shortly after SushiSwap launched, the pseudonymous founder of the protocol, Chef Nomi, withdrew 1bout $14 million worth of Ether from the development fund. Despite being fully legal within the design of the protocol, this transfer engendered an enormous outcry from the community. Sam Blankman-Fried, CEO of FTX and investment firm Alameda Research took on the role of spokesman for the aggrieved SushiSwap participants. A few days later, Chef Nomi tweeted that they had returned the Ether to the development fund.
On November 30, Yearn Protocol Founder Andre Cronje posted a blog saying that SushiSwap would merge into Yearn, subject to votes by holders of each protocol's governance tokens. They plan to develop and launch Deriswap, a platform for swaps, options and loans. Combined, Yearn and SushiSwap Protocols held about $1.185 billion worth of locked value at the time of the announcement.