It's not a scam. Boards like er.org and others require this verification to cut down on spam, meet local regs for minimum ages to participate, etc. When you joined here you had to verify your registration as well.
Several things may have happened....
The verification e-mail may be in your spam folder. It's an automated e-mail and often gets flagged this way.
Some forums moderate new registrations - you may not receive the verification e-mail until a moderator has manually approved your registration - again this is usually a spam prevention tool, try not to take it personally.
If you find that the activation e-mails are in your spam box, you should know that those codes usually are only valid for 24 hours so it may no longer work.
Spam is a huge deal for internet forums - spammers are always winning the game and it takes a huge effort to keep spam to a dull roar. Try not to take the registration process personally