Three simple things to think about before signing up for a newsletter or a business concept:
1. The bigger and bolder and the more colorful the text is in the headlines the more careful you should be.
2. If it sounds to good to be true, it probably isn't true.
3. Even you get something "for free" it is not for free. Especially not if you give away your e-mail address to get the free stuff. It will probably come back on you as spam.
I have noticed that even links from this site through our guest writers or ads goes to "opportunities" that could be doubtful.
