Entrepreneur Andrew Yang offered to give away free money at last week's Democratic debate, and his email list grew many sizes that day.

Yang during his opening statement at the third Democratic debate announced he would give $1,000 a month for a full year to 10 randomly-selected families who entered a raffle on his website. An email address is required to enter the contest, which is meant to showcase his 2020 proposal to give every American adult $1,000 a month in what he calls a Freedom Dividend.

Now, the Yang campaign says more than 450,000 people have entered the contest, Politico reports. More than 90 percent of the email addresses collected were new, the campaign said. The Yang campaign also said it raised $1 million in the 72 hours after the debate, a significant haul considering it only raised $2.8 million in the entire last quarter.

This announcement comes as Yang himself is swearing that his contest is actually legal, something experts immediately called into question. Although Yang has already been giving $1,000 a month away to some families, he was doing that with his own money, whereas this contest uses campaign funds; an expert with the Campaign Legal Center told Politico the stunt is of "dubious legality, at best."

Yang swears it's fine, though, in a Sunday interview describing it as "perfectly legal" and saying the campaign has "an army of lawyers who signed off on it." Assuming he gets away with it, after this success, don't be surprised to see the businessman double down on these game show-esque raffles for the next Democratic debate in October. Brendan Morrow