The couple appeared on the dating show in 2016, finishing second to winners Cara De La Hoyde and Nathan Massey.
They've since married and a series of TV, clothing and magazine deals have led them to amass a reported £4.5 million fortune.
The pair's total is understood to make them the richest stars to have appeared on the ITV2 reality series.
In an interview with The Sun newspaper, Olivia shared: "I didn’t go on Love Island for love, I didn’t go in for money, I just went in for a laugh.
“My friends say I’ve become a nicer person because of Love Island.
“Now we’ve moved into our dream home, we go on amazing holidays and it’s thanks to Love Island."
Even in lockdown influencers like Olivia are able to cash in.
Attain recently did some research into which celebrities were earning the most money on Instagram between March and May.
Olivia was the top earner from Love Island making an estimated £190,000 from sponsored posts while husband Alex notched up £80,000 in estimated earnings.
"We have definitely been lucky but there is no guarantee that you will strike it rich from going on Love Island," Olivia said. "We know people who have gone back to their normal jobs after the show and nothing has changed for them.
“You have to be really savvy to achieve longevity. You have to work hard and make the right decisions.”
This summer's series of Love Island has been cancelled due to the ongoing health crisis.
The show will return as normal in 2021 with host Laura Whitmore saying: "Next year is going to be BIG."
ITV2 will be airing Love Island Australia from June 16 in place of the UK show.
Picture credit: ITV