This story has been corrected. Read below
The monthly telephone survey asking respondents who their favorite NBA player was confirms James' popularity took a hit as the league's popularity rose.
But anecdotal evidence has long indicated NBA fans have a love-hate relationship with the Heat.
"We have about a month left of the hate," James said Thursday night after the Heat ousted the Chicago Bulls in Game 5 the Eastern Conference finals. "We'll see what happens next year."
From April 2010 to last month, 50 percent fewer respondents said James was their favorite NBA player, from a high of
9 percent in the month before his former Cavaliers were ousted by the Celtics in Game 6 of the playoffs' second round.
The poll result fell to 4.5 percent as the Heat wrapped up a 58-24 regular season and blew through the Philadelphia 76ers in the first round this year.
"They're Hollywood as hell, but they're very good," said Bulls center Joakim Noah after Thursday's game, referring to the Heat.
Meanwhile, 14 percent more respondents said this April they were at least "a little bit interested" in the NBA, increasing to 54.7 percent from 48.0 percent at the same time last year.
The data are taken from a 10-year-old phone survey of sports fans done each month by ESPN Sports Poll.
Interviews in 2010 were conducted with 8,003 respondents; in 2011, 6,007 were conducted.
Respondents who said James was their favorite overall athlete dropped from 3.6 percent to 1.8 percent.
In August 2010, during the month after the two-time MVP announced his decision to sign with the Heat in a TV special aired by ESPN, that number fell from 3 percent to 1.6 percent, bottoming out a month later at 1.3 percent.
A May 27 ESPN.com story on results from an ESPN Sports Poll released that day incorrectly stated the scientific nature of the poll. The poll is scientifically based; the telephone survey of fans (6,007 in this case) is done monthly and has been for the past decade.