Relationship Products

I have mentioned this industry already.  It is true that relationship products tend to sell pretty well online.  People are always looking for information on how to better their love life or relationship struggles. 

This industry is wide and can be narrowed down further and further.  Find some forums where relationships are discussed and you are bound to find some ideas on products.

People have abusive relationships, boring relationships, jealousy, anger, bad habits, money problems, communication problems, and so on.

Appealing to these serious emotions with an informational product can be a winner in marketing.  There will always be a market for relationship products.