There’s a lot written about CTR and how to get more clicks. While this definitely has its place, this is not always a good thing. When I first started out, I was always obsessed with getting a higher CTR. Writing goofy or shock and awe ads can usually do the trick, but is this the type of visitor you really want?
I would much rather have 10 clicks looking to take action, than 100 clicks landing on my site just because I had cleverly written copy. You can use ad qualifiers to filter your traffic and hopefully get more bang for your buck.
Below are some common ways to do this:
Include Price
Stating the price in your ad will definitely reduce your CTR, but those that do clickthrough will not be surprised to find on your landing page that you’re selling something.
For Men/Women only
If your product is gender specific, state so. Yes, the reverse psychology is strong and will most likely get the curious clickers, but even if you can get the ratio from 50/50 to 70/30 you still win.
Target Users
This is the same idea as above, but using it in a more general way. Beginners only, 21+, seniors only are all ways to try to narrow your focus to get those targeted clicks in your niche.
What to expect
It may also benefit to test putting your call to action directly in your ad, so when they land there will be no surprises. Is it an email or zip submit, state so … “email only” or “zip only”. If it’s a form to fill out state “simple form” or something. “Buy now” or “purchase today” etc… will also let them know you have something to sell.
As always test this out, you may find it to lower your CTR but increase your bottom line. There will always be a balance to this, as a higher CTR will lower your quality score. That’s something that you will just have to find yourself …. 
You have a good point. I have seen some other bloggers point out how direly important it is to have a high CTR, but there is (as you state) a downside to it sometimes.