It was the "merciless" pursuit of Vello Systems by an Invest NI business development director in Silicon Valley, California which helped the business commit to visiting the province, its chief joked yesterday.
However, he was swayed after meeting representatives of other US technology companies which have set up here, such as SAP, the world's third largest software company which has a low-profile presence in Belfast.
"The local Silicon Valley Invest NI team approached us and got a meeting and walked me through the pitch.
"I travel to Europe fairly frequently and they said 'come to Belfast and we'll show you around'. That was September last year and I was really, really impressed with what I saw," he said.
Belfast is its first major office for product development and 'real' engineering outside the US, though it also has sales offices in London and Germany. In fact, Germany almost beat Belfast into second place as a new location.
"We had been talking on and off a long time with folks over in Germany.
"If you pick the right part of Germany you can get an extremely attractive economic package so purely from economics there is some very, very tough competition from some parts of Europe for Northern Ireland.
"There are some reasons that that was attractive but there were some logistical reasons that it was unattractive," Mr May explained.
The Republic was also considered but ultimately Belfast won out, with Mr Gray finding some "very, very compelling people here who could act as anchors for the organisation". Ultimately, the staff in the Belfast office will focus on the "core functions" of the company – engineering and product management and support.
He reluctantly weighed in to the debate over technology companies such as Apple which have set up operations in the Republic only to face challenges over their tax affairs. Mr May said: "For American companies the US corporate tax regime requires a dramatic overhaul. That's all I'm going to say."
But Mr Gray said no company made investment decisions purely over tax.
"There were lots of reasons for coming here and I doubt that any businessperson makes a decision for tax.
"That's a rather silly over-simplification," he added.