Just because an email is spam does not necessarily mean that is is also a scam.
However, it certainly is an annoyance nonetheless.
Whilst most people associate spam with adverts for pills, potions and other dubious products and services it is, in fact, simply the receipt of any email that is unsolicited.
Of course some unsolicited email can be of the scam variety too, typically being advanced fee scams and phishing attempts.
Bulk Email Delivery
Spam is profitable to those behind it because huge amounts can be sent in a very short period of time.
The cost is virtually nil as well as even an extremely low success rate can net huge amounts of money for the operators.
Bulk emailing clients are used to distribute spam to thousands of email addresses virtually at once.
Whilst spam filters will block most, and human readers will delete large amounts, some spam will still get read simply because of the volume that has been sent.
For this reason spam is likely to continue and increase for years to come.
Lack Of Deterrents
In many countries of the world there are strong laws which outlaw spam.
However, spammers will typically originate from countries where such laws do not exist or are not enforced.
When you receive spam email the best policy is to not even open it and certainly do not click on any links within such emails as they may take you to fraudulent websites or otherwise give personal details to the spammers.
At best this could lead to your information being added to lists that contain information about people who read spam, thereby leading to an increase in the amount you receive.