Subway is making an epic comeback at the best possible time

• Subway's global same-store sales surged by more than 12% in the most recent quarter, the chain said.
• Digital sales grew about 20% in North America, boosted by deals for app users.

Subway is turning things around, and even a scathing documentary reminding the public of its former spokesperson's abhorrent behavior can't stop the sandwich chain's progress.

Subway, which as a private company only shares periodic updates to its financials, announced on Monday its ninth consecutive quarter of positive sales. In the most recent quarter, global same-store sales surged by more than 12%, the chain said.

The timing for Subway is ideal, as the company announced in February that it was exploring a sale for $10 billion. Recent interviews with Subway's CEO indicate that the sale is imminent.

"We'll have it signed sometime the end of May/beginning of June," CEO John Chidsey told Restaurant Business.

Chidsey has big ambitions outside the US. He told Restaurant Business that Subway currently has 16,500 stores overseas but believes it should have 40,000 or even 60,000. The chain currently has 37,000 restaurant locations in total.

Subway's recent menu updates have helped spur growth. The changes included adding new breads and other ingredients, introducing a standardized sandwich list, and rolling out deli meat slicers to stores.

The company said its quarterly digital sales saw a boost of about 20% in North America, no doubt boosted by promotions like 50% discounts for its footlong sandwiches to app users.

In February, Subway's app was the third-most downloaded fast-food app in the US, logging 1 million downloads, Apptopia said in an article published in QSR Magazine.

Still, the company has faced some recent hurdles. Some feared a documentary about its former pitchman Jared Fogle could bring unwanted attention at a crucial time for the chain. Fogle became famous for losing 245 pounds by mostly eating the chain's subs and was later caught paying minors for sex and trading child pornography.

The company appears confident that its turnaround is working, however.

"Our continued impressive performance demonstrates that our efforts to build a better Subway and win back the hearts and minds of sandwich lovers around the globe is working," Chidsey said in a statement.