This undated photo released by Yamaha Entertainment Group shows a custom-made purple piano the company manufactured for musician Prince. (Yamaha Entertainment Group via AP)

Following Prince’s death last Thursday, the nation mourned. Condolences and tributes poured out of cities and social media sites, honoring the Purple One. The Internet swelled with thought-pieces and reflections.

But at the heart of Prince was the music. Tellingly, his record sales have skyrocketed by 40,000 percent, the Los Angeles Times reported.

At a 70,000 percent rise in sales, hits compilation “The Very Best of Prince” experienced the largest jump. A quarter million copies were sold. “Purple Rain,” arguably Prince’s most well-known record, sold 133,000 copies.

During the weekend, 2.3 million of his tracks were sold as singles, a 33,500 percent increase. Naturally, sales of “Purple Rain” were highest: 287,000 copies.

It’s a commonly occurring paradox: an artist’s record sales see incredible spikes just when he or she is no longer here to enjoy the rewards. In Prince’s case, it’s unclear at this point who will inherit his estate. The Associated Press reported that though he owned about $27 million in property in and around Paisley Park — to say nothing of proceeds from his record sales or the value of his vault of never released recordings — it remains unclear if he had a will.

He wasn’t married, nor did he have any known children. If he doesn’t have a will, his estate will likely be shared by his sister Tyka Nelson and his five half-siblings. And it’s likely that estate will continue to grow.

The estates of famous musicians often become extremely profitable after they die.

“Our research indicates death-related publicity serves primarily as informational advertising that informs new customers,” said University of Warwick assistant professor of marketing Leif Brandes in a blog post on the school’s website. “However, complementary survey evidence reveals that death-related publicity also triggers considerable nostalgic reactions and personal mortality salience – a feeling of their own mortality – from existing record-owners.”

This, he said, generally leads to a more than 50 percent boost in records sales following an artist’s death.

This analysis appears to be borne out by the recent passing of famous recording artists.

In the first three weeks after Michael Jackson’s death in 2009, the deceased King of Pop sold more than 9 million copies of his albums, the Los Angeles Times reported.

“They aren’t just buying ‘Thriller’ but a broad range of titles from throughout Michael’s career,” Gary Arnold, then senior entertainment officer for Best Buy, told the Los Angeles Times in 2009. “Realistically we expect to see people connecting at unprecedented levels through Christmas.”

In the four days after Amy Winehouse died in 2011, her record sales experienced a 37-fold increase, according to Billboard. Less than a month after Whitney Houston was found dead in a hotel bathtub in 2012, she became the first woman with three albums in the top 10 of Billboard 200’s chart, Billboard reported.

Sales of David Bowie’s records increased by more than 5,000 percent in the week following his death in January, Billboard reported.

Some artists continue to have lengthy careers long after death takes them. So much so that Forbes long had an annual “Top-Earning Dead Musicians” list (which appears to have morphed into a “Top-Earning Dead Celebrities” list last year).

According to Forbes, Bob Marley has sold more than 75 million records since his death in 1981. In fact, his 2015 earnings — these include record sales, licensing deals and other items — of $20 million were up by $2 million from the preceding year. John Lennon’s sales hit $12 million in 2015. He was killed in 1980.

For some high-profile artists, death can prove extremely profitable.

“It’s massive business,” Kelvyn Gardner, UK managing director of the Licensing Industry Merchandisers’ Association, told The Guardian in 2014. “In the US there are whole agencies that have grown up to represent deceased celebrities, and they’ve made substantial business doing it. In some cases their whole portfolio of rights consist of dead people and dead brands.”

Prince’s posthumous career, in particular, could be one of the most profitable.

Mark Roesler, chief executive of CMG Worldwide, which controls licensing for the estates of late stars, including Marilyn Monroe and James Dean, predicts Prince’s posthumous career will be similar to Elvis Presley’s, who has repeatedly held one of the top slots the Forbes’s annual list. In 2015, his estate earned $55 million.

“He was as big as they get,” Roesler told the Associated Press. “Will there be a business built up around Prince 60 years from now like James Dean? The answer is unequivocally yes.”

Though record companies normally see a financial reward after an artist’s death, that might not be the case this time. Before dying, Prince had recently taken full control of his music rights, including copyrights for songwriting, the New York Times reported. That’s one reason why his music doesn’t appear on many popular streaming services, such as Spotify.

L. Londell McMillan, lawyer and former manager of Prince who was also Michael Jackson’s lawyer, declined to comment on whether Prince had a will, telling the Associated Press, “I want to make sure his legacy is respected and protected no matter what role I play.”