Title. I'm slangin diet and need moar trials.... I prefer a specific offer, but the network says capped till March 1st, so I'm running other stuff now.
Is this an all across the industry cap, or just for that one network?
It depends on the advertiser. It could be industry, it could be network, it could just be your pub id.
It could be either.
Genreally an agency is given a budget which is shared out over affiliates.
Certain affiliates will get a larger budget if they have proven to supply quality leads in the past.
Quality over Quantity.
I wonder how do you know when you hit your cap? The offer will stop converting, do you get an email or they will just cut your earnings for that day?
Caps are usually assigned to you as a pub. Especially on diet and other trial type offers. It is rather unusual that you get a super high performing trial offer without caps, because then everyone would blow the crap out of it. Which means for a lot of pubs that you should be extremely cautious if you get a trial offer that doesn't have caps (hint: It probably doesn't convert as well as other offers out there). Also, no caps would mean that the advertiser doesn't care about the quality of leads. On a trial offer that's also strange, because the advertiser has to be concerned about rebill rate when the trial period ends (and thereafter for rebills).
Now what happens when you hit your cap?
There are several options, and this depends entirely on your network and your relationship with said network or AM. The network can put a hard cap into place, let's say 100. After 100 leads the network then has several options. They can 404 your traffic, probably the worst of all options. They can also redirect it to another offer and either pay you on leads generated on that offer, or not pay you at all since you are going over cap. A good network will notify you on a hard cap and automatically send you emails when 50%, 75%, 80%, 90% of your cap are reached on any given day.
The soft cap is more of a flexible agreement between you and the AM. Flexible in a sense that your network still wants you to comply with said cap, but they are ok with you going over by X% on a given day - For instance if you'd only do 75 out of 100 on day A, but then 125 out of 100 (so 25 over your cap) on day B - they may tolerate it. You'd usually get a friendly reminder/warning, which helps you analyze your traffic and throttle a bit for the next day.
As a new pub starting with the network, you will most likely get capped, just so the network and advertiser can analyze the quality of your traffic after the trial period ends. As a seasoned pub with the network you most likely get larger cap and more flexibility as well.
You can have either click caps (# of clicks allowed per offer - rarely happens), or conversion caps as mentioned above. Conversion cap interval could be either daily, weekly, monthly or for a custom and predefined period of time.