Target = _blank .. bad etiquette?

I had a suggestion from a friend to update my website to include target = _blank for outgoing links.  It kind of makes sense from a marketing point of view since the user is being kept on my site.   Personally, I know how to hold down the ’shift’ key when I click on a link to force a new window to open, but does the target demographic know that they can do that, probably not?  Anyway, the conclusion I have come to is that to unexpectedly open a new window will possibly annoy some people and disappoint others.  Someone made a very valid point on this forum being that to use target = _blank, you are not giving the user a choice.

I have decided to refrain from using target = _blank for the moment hoping that people at least know how to use the ‘back’ button