"I'm done. I've made this resolution that I'm going to be much kinder about Costolo, and he can stay," Cramer said on "Squawk on the Street" on Monday.
However, his support is contingent on Twitter monetizing its service. He cited SunTrust analyst Robert Peck recent research, saying Peck's calls on Twitter have proven trustworthy in the past.
Peck believes the microblogging service could accelerate growth in monthly average users as it introduces more "'business development' type deals with deeper integration into top apps." He also sees Twitter supplying targeted native advertisements.
"The culmination of these deals this year could create Twitter's 'Facebook Moment,'" Peck wrote, referring to the point during the summer of 2013 when investors turned positive on Facebook, sending its shares higher.