I've always been concerned with being polite and exercising proper reciprocity when it comes to manners; someone sends you a gift, you send them a thank you note (or email, or text); a friend does you a favor, and you try to return it by taking them out to dinner or buying them a cup of coffee. It gets a little hazy, however, in the online world and with social media, as there doesn't seem to be a clearly defined set rules for dos and don'ts on this platform. Until I decide to assume the role as the Emily Post of the blogosphere, I've put together a quick list of situations and my hypothesis on proper etiquette for each, which is really just based on speculation and experience as to what I feel could be the right thing to do:
If someone retweets something of yours or Likes or Favorites it, do you say thank you?
If someone comments on your blog post, and he/she has a blog of his/her own, should you comment there as well?
If Facebook friends start following your feed on Instagram, should you follow the back?
When attending an event, reviewing product, or participating in a promotion and a hashtag is provided, should you feel obligated to use it in a Tweet/Instagram/Foursquare check-in, etc?
I think there is an unspoken understanding that yes, it is rather expected/asked of you to share to your followers from your point of view by using the given hashtag.
I don't mean for you to do it ad nauseam, but I think just once will certainly suffice. If the hashtag/twitter handle is prominently displayed as part of the note to you from the publicist or visible at the event, I think you definitely should find a way to share what you are seeing/doing in a way that fits your style and voice. It depends on what I'm doing and feeling, if I will tweet during or after an event, but if I experience something that I really am into and want to share with readers, I will certainly share some of my enthusiasm via social media, and tag the brand/person/designer/ event.