Twitter’s business mojo is waning as their latest quarterly reports shows slowest revenue growth since IPO in 2013. Shares took an immediate hit and saw Twitter’s down more than 10%. Since then, Twitter has lost more than $1.5 billion cumulatively.

The popular microblogging service is looking at a stagnating user increase, running on rising cost instead of revenue. The main disappointment sees a less than stellar revenue from advertising with rivals Facebook and Snapchat sweeping up more dole and taking the lead in the advertising arena.

For Twitter, advertising revenue in the fourth quarter declined 0.5 percent year-over-year to $638 million, and the company said that advertising revenue growth would continue to lag user growth during 2017.

Twitter has been a subject of interest in terms of their failing business model for quite some time now. Numerous speculations on whether the social media firm will be bought has become the water cooler talk for tech and market analysts alike. Reuters has commented that Twitter “has struggled to find a formula that will attract a new crop of users or advertisers even as rivals have ridden a wave of rising investment in internet advertising.”

Reuters reported that the company was revisiting core advertising strategies, and quick turnaround of revenue was unlikely. In fact this quarter saw a revenue of $717 million, well below analyst expectation, with experts predicting a further loss of revenue in the next couple years.

According to Reuters, “[Chief Executive Jack] Dorsey told analysts on a conference call on Thursday that Twitter was investing in machine learning and searching for ways to engage advertisers.” Dorsey told analysts that whatever is in the works, it’ll takes time before any concrete results can be seen. He’s not wrong saying “The whole world is watching Twitter.”

This report is sourced from Reuters, more information and reports by Reuters here and here.