If your to deceptive like "$5 Dinners in Country" would that have a negative effect on your campaign?
That really depends, I have seen deals like that before so it's not necessarily deceptive.
To be safe, you can advertise to the limit of what the offer itself usually advertises, 50%, half-off, 2 for 1, up to 90% off, etc.
I'd say TEST IT.
The only negative effect i can see is a lack of quality from your leads, and getting cut from the offer. Your leads technically need to translate into buyers, so keep that in mind when creating your campaign, especially if your doing any significant volume.
Example:
A campaign around food, or traveling will probably = more sales for the company, then a campaign around 90% off homes in Texas.