The New Jersey Blood Services is working with a three-day supply, which is considered critical, said representative Marie Forrestal.

A 10- to 14-day supply is optimal, and anything below a five-day supply is critical, she said.

During the last six months, local blood drives have been offering incentives to donors, such as gas cards, store gift cards, and even Mets tickets, to try and boost the number of donors.

“We think of it as positive reinforcement for them doing their good deed, and blood centers all across the world have been giving their donors little gifts throughout the years,” Forrestal said about these incentives.

While Forrestal said it was too soon to tell if the incentives have increased the blood supply, Mikki Carpenter, manager of donor recruitment at the New Jersey Blood Center, said, “We are not in what we would call emergency shortage.” One of the reasons for that, she said, is that “these promotions have brought in a good deal of blood.”

The New Jersey Blood Center had a blood drive at Wal-Mart in Newton last week and gave out $20 Wal-Mart gift cards to all the donors.

Maureen Scarpone, of Newton, stood outside of the bloodmobile thinking about donating her blood for the first time but the needle “kind of frightens” her. She did acknowledge the gift card persuaded her a little but she mainly came out because her friend was giving blood.

“I just like to do it,” said Mary Sullivan, of Newton, who has been a donor for two years. Her first time giving blood was between college classes and she just thought “I’ll do it.” She said her decision to give blood “has nothing to do with receiving a gift card.”

Heather Stromberg, of Budd Lake, said she tries to donate a couple of times a year ever since 9/11 happened.

“It’s my blood so it’s nice to get a little something back,” said Stromberg, who said the incentives don’t decide if she donates or not, but they did sway her to come to that specific site.

The incentives started when gas prices started soaring, Forrestal said, as a way to help make up for the increased cost to the donors to get to a blood drive.

New Jersey Blood Services also started an online program called Red Cell Advantage about six months ago where anyone who gives blood automatically starts accruing points. A regular blood donation is 75 points and an automated red cell donation is 200 points. Donors visit www.mydonorrewards.com to track their points and pick gifts, which include an iPod car adapter for 400 points, a DVD player for 800 points, and the Wii video game “Rock Band” for 1,600 points.

Carpenter said the incentives are to “entice new donors into the system … especially among minorities.” Encouraging members of minorities to donate blood is the center’s biggest goal, according to Carpenter, because some “minorities’ blood is somewhat rare.”

A New Jersey Blood Services’ press release earlier this month stated a special need for Rh negative blood types. The press release also stated “about 50 percent of the blood donated in New Jersey comes from corporate blood donors … and the recent downsizing of many of our financial institutions will be negatively impacting blood collections for the foreseeable future.

According to Forrestal, employees from Lehman Brothers, which declared bankruptcy earlier this year, used to donate 400 pints of blood each year.