It's a big week for Jack Dorsey in more ways than one. The new Twitter CEO's other company, the payment service Square, has filed for an initial public stock offering that's tentatively worth up to $275 million. It's not certain just when shares will be available. However, the move shows a belief that Square's hopes of reinventing the purchasing process (through everything from readers to food delivery) have legs. As it stands, investments might be necessary in the short term. While Square's bottom line is improving, it continues to lose money -- $77.6 million just in the first half of this year. Going public gives the firm more breathing room, and may sharpen its focus. After all, it's about to have the expectations of many, many people riding on its shoulders.