It will show what ever you write in the subject line but it will still come up under the thread you replied to. Gmail
"stacks" all replies under the same thread and only shows
the oldest unread email until you click on it. The it expands
to show all the replies. Even if you change the entire subject
line when using the reply feature it will still appear in the 
"stack" of the thread you hit reply on. Confusing to
have this make sense and be readable. 
Bottom line is
don't use reply to start a NEW post. Start an entire new email
if you want the most visibility. 

Bill

On Jun 22, 2012, at 4:13 PM, Scott Daniel - Turbovans <scottdaniel@turbovans.com> wrote:

> Does it show the change  if you just add a few words to an existing subject -thread ? 
> 
> On 6/22/2012 11:59 AM, Bill M wrote:
>> 
>> I don't know if people know this but:
>> 
>> When you are starting a new topic and use reply off another
>> thread but erase the old subject. The new subject is still listed under the thread you erased in Gmail and other email
>> programs. If you want the most exposure to your new topic 
>> be sure to avoid using the reply on an existing subject. 
>> I don't read every thread and have missed emails because of
>> this. Just an FYI for those who dont know. 
>> 
>> Bill