BetterZip 2 supports two services: one for extracting and one for creating archives. You can configure what the BetterZip services will do with presets.
To use a service, select one or more files or folders in the Finder and choose Compress with BetterZip or Extract with BetterZip from the Finder > Services menu or the Services submenu in the contextual menu.
You can even set keyboard shortcuts for the BetterZip services, e.g., ^⌥⌘C for compressing and ^⌥⌘E for extracting. To set shortcuts for services, go to System Preferences > Keyboard > Keyboard Shortcuts and choose Services in the left table. In the right table, scroll to Files and Folders, choose Compress with BetterZip and press ↩. An editable textfield will appear. Press the desired shortcut.