The flow of the idea is the following:
1) You register at for free (if you haven't yet:-)

2) Create an offer and put it to the marketplace - there are many other offers from different advertisers.

3) Affiliate network then can see this new offer in the marketplace and start to work with the new advertiser.

4) You don't need to create the offer for each network.
The creation of one version of the offer will be enough, If several networks will want to work with the advertiser.
Would you like to list your offers on this type of marketplace?