In some occasions, you may want to inject into your lander/offer URLs some text selected randomly from a list of options you provide yourself.

Here is how to do it for landers (it is similar for offers).

Start by clicking the "Custom Fields" button next to the URL:

This will open a popup window in which you will be able to enter all your different text options (one per line):

Click ok.

Now, use the token {customfield-random} in your url, where you want one of these text options to be injected.

This token will then be dynamically replaced by one of your provided options everytime a visitor is redirected to this lander.

You can use this when you want to vary content on a page for some reason, to spoof details into a URL (e.g. to confuse competitors), and you can do the same in offer URLs -- e.g. if you need to pass something like publisher IDs, but you do not want to reveal these for privacy reasons, so you instead send random ones.

Another example would be spoofing random details like bid or cost=0.017 and so on into landers to confuse competitors who may try to use this information in a bidding war (to their own detriment).