How much revenue does it takes to earn an eleven-figure valuation? Alex Wilhelm 8 hours News broke last night that Affirm, a well-known fintech unicorn, could approach the public markets at a valuation of $5 to $10 billion. The Wall Street Journal, which broke the news, said that Affirm could begin trading this year and that its IPO options include debuting via a special purpose acquisition company, also known as a SPAC. That Affirm is considering listing is not a surprise. The company is around eight years old and has raised…