After a string of ugly one-night stands, Wall Street found love with Yahoo CEO Marissa Mayer. The pair had a sweet honeymoon period: Yahoo's share price has more than doubled during her first 18 months as CEO.

But with the company's latest lackluster earnings report Tuesday, following the very expensive firing of key hire Henrique de Castro -- a "regrettable conclusion and something we tried to avoid," Mayer said -- it seems the honeymoon is over.

On an earnings call Tuesday, Mayer stressed that Yahoo's turnaround will take years, and her focus on people and products has positioned the company for a "chain reaction" of traffic and revenue growth in 2014.

Unfortunately, Wall Street's patience for turnaround CEOs has shrunk over the past decade. Typically a CEO gets eight quarters to execute a turnaround, down from 16 quarters in the '90s. Mayer's predecessor at Yahoo, Scott Thompson, came and went even faster than that. Before him, Carol Bartz lasted two years and nine months. Jerry Yang, a co-founder, lasted just 18 months.

Luckily, Mayer joined Yahoo just after the company sold half of its stake in the Chinese e-commerce giant Alibaba, giving Yahoo more than $7 billion in cash for stock buybacks and $1.1 billion acquisitions like Tumblr. This, alongside anticipation of an Alibaba IPO in 2014, has kept investors from losing faith in Yahoo thus far. It may not last much longer.

http://tech.fortune.cnn.com/2014/01/28/is-time-running-out-for-marissa-mayer/