This spam problem exists everywhere, I really hate these spammers that are useless and gives no added value! they cheat to make money like cowards. But I'm sure there will be techniques to detect them.
For example, I give a simple technique:
When someone writes a comment you just have to write him an answer that requires a special response from him, and that way you'll know if he's a spammer or not.
In my opinion also people who often write standard comments like "Nice post" "" Great job "... are 90% of the spammers.
