The cost of advertising spots for Tucker Carlson Tonight have nearly doubled in the last year despite numerous rounds of boycotts by advertisers.

The analysis, which was done by the media research firm SQAD, found that advertising spots for Carlson's show had gone up from an average of $11,099 for a 30-second spot in July of 2018 to $21,878 for the average 30-second spot in July of 2019.

Carlson, 50, has seen a sharp increase in cost of ad spots this spring and summer, with his show demanding an average of $13,289 a spot in March but an average of over $20,000 a spot in proceeding months.

In contrast, late night MSNBC-rival Rachel Maddow saw only a moderate increase in cost of ad spots. In July 2018, a 30-second slot on her show cost advertisers an average of $8,292, but that figure only increased to $10,044 in July of 2019.

Carlson has seen dozens of advertisers flee his show in the last year, including Pacific Life and Farmers Insurance. Recently, lending start-up SoFi and meditation app Calm also deserted the show.

In December, Carlson said certain immigrants make the country "poorer and dirtier," which led to a first round of boycotts. The liberal advocacy group, Media Matters for America, led another round of advertisers to leave Carlson in March after they published vulgar excerpts from the host calling into the "Bubba the Love Sponge" show. Some activists called for another round of boycotts this month after Carlson described as " a hoax" the idea that white supremacy is one of the nation's most pressing problems.

The show's high-dollar demand for ad slots can be chalked up to customers rewarding loyal companies that had the "courage" to stay with Carlson, according to SQAD.