Some social niceties are clear-cut rules, like “Don’t spit in public” (or the high-falutin’ version, “Don’t expectorate in front of the ladies if you expect to rate with the ladies”). Others are general guidelines, in which you should use your own judgment. This one is in the latter category.
In general, don’t thank people for Retweeting you. If you are particularly grateful, and you think it will make the recipient feel all warm and fuzzy to get a private note of appreciation, send the person a simple DM (“Thanks for RTing my link to the article about birds in Belize!”).
Some people do send these thank-yous publicly; however, they usually do it in a single Tweet thanking several people at once:





