Their relationship has often been described as a match made in heaven, but it looks like Kanye West and Kim Kardashian's romance may not have the blessing of many of his fans.

According to new figures the rapper's popularity has plummeted by 66% since he started dating the reality star.

Research by Q Scores, a US website that measures the appeal of a brand, reveals that West had a high score of 17 among women aged between 18 and 49 before he and Kardashian began dating in April 2011.

But since the couple became an item, it has now dropped to three in the women's 18-49 category. There has also been a plunge in likeability amongst his core fan base, which is men aged 18-34. His score is now 13 compared to 19 at its highest.

"Kanye has had a significant drop among women. It's surprising," Henry Schafer, Executive Vice President of the Q Scores Company, told

The fall in popularity is said to have been caused by public clashes with the paparazzi and fellow celebrities.

A source told "Kanye has emphatically told Kim that he believes they're going to be the biggest power couple on the planet.

"He genuinely thinks they will be more popular than his close friends, Jay Z and Beyonce."

Their romance has also negatively impacted Kardashian, who now has a baby daughter with the rapper.

The mother-of-one's popularity is also on the downslide and her score dropped from nine in 2011 to four in September 2012.