Sure, it comes in different flavors. Some of my favorites include, "This is a total scam, dude!"; "I've seen scams like this before!", and "No way, people fall for this scam??"
I looked it up. According to the fine folks at www.m-w.com, the word scam is simply defined as such: a fraudulent or deceptive act or operation. OK, that's pretty loose. I mean, how many "deceptive acts" do we deal with on a daily basis? TV commercials, reality shows, political debates? When you really think about it, it is hard to be persuasive without some degree of deceit. And that's all advertising is; persuasion. Unless you want to live thinking the whole world is "a scam", I think you can only focus on the "fraudulent" part of Mr. Webster's definition.
Fraud is a whole other subject. To me, fraud in network marketing is indeed something to be wary of. I'm sure there are examples of businesses that started only to take money from a few trusting individuals, then shut down and take the money and run. Still others only collect e-mail address for the purpose of selling them.
What you will find is more prevalent, however, are smaller transgressions, such as improper statistics. For example, most sites will show how "Jim made $5000 in 2 days". Is this fraudulent? Probably not.
Here's how to protect yourself
If you've made the decision to persue a network marketing business, either via internet or not, you MUST look at all claims using your own sense of reason. First off, assume that all the advertising you hear and read is true. Most likely, every claim you read is verifiable in one way or another. Secondly, assume that the same WILL NOT happen to you.
Read this carefully. I am NOT saying you will not make money. I am NOT saying the advertising is deceitful or fraudulent. I AM saying what most people won't tell you. It is highly, highly unlikely that your immediate results will mirror those you hear about. Of course there is a chance, but if you assume that "you will be different", you are going to be disappointed.
Do not forget that network marketing is first and foremost a business. It is not a magic potion to cure you of suffocating debt and daily financial woes. It takes time, patience, courage, risk, capital, understanding, education, and (once again for emphasis) time!
Make sure whatever business you start has at least these two things. One, viable marketable products that are in demand. Two, a strong training and support network, preferably of people whose success depends on your own.