Hashtags were something that became more popular when Twitter opened, I remember people using them for the most craziest of reasons. Since Twitter has grown more popular now people tend to use hastags to gain more exposure which can sometimes work really well.
Facebook recently has also jumped in and started the usage of hashtags on their social media website, again some people use them for the most craziest of reasons but you do see people using them to help gain exposure.
My question is how affective are hashtags in social media? Have you used hashtags and found that they have worked well for you?