Well, the German Greens don't have membership cards either.
With joining the party, you're added to their internal mailing lists (which you're free to unsubscribe) and your bank account is debited with the monthly membership fee (the exact amount of your membership fee is determined by yourself). That's basically it.
Internal votings are also handled somewhat... lax. Technically, any person is allowed to vote there, even non-members. To achieve this, they devised a somewhat complexer process which bends the law without actually breaking it (at least I hope so). Maybe I should stop writing now, otherwise I could get them into trouble.
![Tongue](https://talkelections.org/FORUM/Smileys/classic/tongue.gif)