Short answers, pulled from the story.
Seltaeb was a merchandising company set up in 1963 by Nicky Byrne to exclusively manage merchandising rights on behalf of Brian Epstein and the Beatles. The name is "Beatles" spelled backwards. Through a poorly negotiated contract, the company retained 90% of all licensing income, leaving only 10% combined for the Beatles and NEMS Enterprises.
The Beatles and NEMS Enterprises lost an estimated $100,000,000 in potential income through the Seltaeb arrangement. The court battle that followed also caused Woolworth's, Penney's, and other companies to cancel merchandise orders worth $78 million.
Nicky Byrne was a 37-year-old Chelsea socialite, ex-Horse Guard trooper, and amateur racing driver with no prior merchandising experience. David Jacobs, Epstein's lawyer, offered him the assignment at a cocktail party. Byrne delivered the contract with the percentage left blank, and when asked what figure to insert, said "just put in 10%." Epstein signed it without negotiating.
The Wall Street Journal predicted American teenagers would spend $50 million on Beatles merchandise during 1964. The Reliant Shirt Corporation sold over a million Beatle T-shirts in three days after paying $100,000 for a licence. The Lowell Toy Corporation was selling Beatle wigs at more than 35,000 per day.
The legal dispute involved 39 individual claims against NEMS and took three years to settle. Byrne won the case, and Epstein paid the court costs and legal bills personally. The judgement was later vacated, meaning it was rendered null and void.
Brian Epstein died on the 27th of August 1967 from what was ruled an accidental overdose of a prescribed drug. David Jacobs was found hanged in his garage on the 15th of December 1968; days before his death he had asked for police protection. Nicky Byrne retired to the Bahamas on his yacht, later moving to the Trowbridge area of Wiltshire.