I forget if this effect has a name, but I believe that the inclusion of incorrect grammar and spelling is exactly what convinces a certain subset of the populat

I forget if this effect has a name, but I believe that the inclusion of incorrect grammar and spelling is exactly what convinces a certain subset of the population that the message is genuine. They don't completely trust messages that are super polished, preferring to give more weight to things that they perceive as "written by a human somewhere." In some cases, these are people with a strong distrust of "mainstream" communications, possibly assuming that anything written well or from certain sources carries an agenda that they don't want to be part of. In other cases, people may just be naive enough to believe that a company with a professional writer on staff wouldn't need their money and that therefore a company without a professional writer (which then writes with occasionally poor grammar and spelling) is more in need of support. In yet other situations, people may have become over-zealous in their support for social sensitivity and feel a strong urge to "help that poor boy in Nigeria." There are probably a lot more reasons this works on certain people, and a lot more types of people that this works on.