What do they mean by that?
I get they mean to try a different offer, but why would the offer be worse compared to a similar offer? Does it mean the offer's landing page is no good? The incentive they're offering is no good? Something else? Which one do you find is more common?
Could be lots of things, really.
Here are some reasons off the top of my head:
-The offer is saturated - lots of affiliates have been promoting it and chances are some of the visitors that see your ads will already have installed the app / signed up to the offer before.
-The offer is old - you'd be competing with affiliates that have had a lot of time to optimize their banners/landers/placements/bids/targetting options etc.
-The offer doesn't convert well enough for its payout - the offer page isn't enticing enough to convert the visitor, the advertiser's backend funnel isn't effective enough to squeeze money from each lead, offer page / redirection times are too high, etc. etc.
-Too much lead shaving/scrubbing going on behind the scenes
And then there are factors that are not intrinsic to the offer itself: You may be running the offer on a traffic source that doesn't convert the best for the particular offer type, for example.
Amy
Is there anything you can do if the offer page looks shady or the form is too long? Have you found good landing page copy to overcome that, or should you always expect a lower CR?
Also, are there any techniques to recognizing lead shaving?

I agree with Amy.
If the offer doesnt look appealing to you (LP, Form, whatever) than why run it? Most chances are that users wont find it appealing as well...
But, if you really feel an offer has potential but needs to be worked on, let your AM know. If you come up with good points than maybe something can be done with the advertiser.
Most of the time, they dont make money with it, but doesnt prove that you also cant.
Should test and feel the process finding the correct path