Ostrofsky is known for his record-breaking sale of the Internet domain name Business.com for $7.5 million—the most expensive domain ever sold at the time—that landed him in the 1999 Guinness Book of World Records. He had purchased the name for $150,000, which had created a media frenzy, with one headline reading “A Fool and his Money were just parted.”

Marc sold the domain name eflowers.com in 1999 to Flowers Direct for $25,000, plus a 50 cent commission for every sale on their website. He had purchased the domain 2 years prior for just $70. But the part of the deal that got the most attention was the delivery of a dozen roses to his wife every month for the rest of her life. 

Marc likes to say that “the riches are in the niches.” He recognized the potential straight away with this very niche product, investing in the company and helped grow the online business. He sold the company in 2018.

Ostrofsky invested in Jay Steinfeld’s window covering and blinds business, the first outside investor in Blinds.com and a member of its board of directors. He helped transform what originally was two retail stores and website on the domain nobrainerblinds.com into the #1 e-commerce site for window coverings and blinds. The business grew to $100 million in revenue by 2014 when it was sold Home Depot.

Ostrofsky made a deal with a third party that ran a much larger and well known ticket site selling discount tickets for sports, concerts, theater, and broadway. His site simply pointed traffic to the other site, and he received a commission from any purchases made through his domain. He received an offer and sold the domain in 2023 after the Ticketmaster debacle with Taylor Swift’s Eras tour put online ticket sites in the news.