Just gotta test it man, your CTR will be lower but that doesn't mean it can't work, especially if you have something niche. I say it's worth a try for sure but don't get your hopes up too much
Trafficjunky is one of those networks where usually even the "remainders" have pretty good quality, so dont hesitate and go for it. For example on exoclick, these cheap clicks are usually worth way less than the first impressions. Its different from network to network, based on the algo they use. But with trafficjunky, I had good results even with these left-overs 
I stopped using exoclick all together, I was getting about 20% of bot traffic from exo. going to test out TrafficJunky and Star next. Just my 2 cents.
KK
Hi flyingcake,
As said above, we have quite a few members that have great success (and better ROI) when bidding low on some spots.
It depends a lot on the offer and the quality of the landing page.
Also, just to make sure it's clear: being the lowest bidder (provided that it would grant you SOME) traffic does not mean that you would get the "bottom of the barrel" impressions.
The ranking shown in the bidding table is NOT the order in which we show the ads.
Each impression is random.
Of course, the higher the share of traffic, the more chances you have to be shown in the first 3 impressions, but the lowest bidder might be shown first for a visitor and then tenth on the next.
It's mathematical: you have 10% of the spot's traffic, you have one out of 10 chances to be shown first 
You will never know until you test 
Give it a test run and go from there.
If you're bidding on keywords you're going to want to bid higher, not lower. The more general your targeting, the lower you can bid.