Second-quarter profits rose from $228m to $335m in the period, but revenues fell 7% year on year to $1.14bn.
Mayer, who arrived at Yahoo from Google exactly one year ago, said that she would award the business an "A" grade for its progress in mobile during that time, and that the company’s culture had changed considerably.
During the period, Yahoo has launched new services in news, sports and weather, and redesigned Yahoo search, in addition to announcing nine acquisitons, including Tumblr and Summly. It continues a strategy to develop four core business areas - search, mobile, display and video - to drive growth.
Mayer said: "This quarter drove tremendous improvements in our product line and our users responded with increased usage and engagement."
She added: "I'm encouraged by Yahoo's performance in the second quarter. Our business saw continued stability, and we launched more products than ever before, introducing a significant new product almost every week.
"We have created a new, super-charged Yahoo. The energy and excitement on campus is unbelievable."
Despite the optimisim, Yahoo continues to lose ad revenues, reporting double-digit falls in display ads, down 11% to 432.1 million in the quarter.
There was a strong growth story emanating from Asia, where Yahoo’s 24% stake in Chinese e-commerce company Alibaba generated a 71 per cent lift in revenue to $1.4 billion. However, the company was forced to scale back its full-year revenue expectations from $4.5-$4.6 billion to $4.45-$4.55 billion.