Have you looked at the available wordpress plugins?

https://en-ca.wordpress.org/plugins/affiliates-manager/

You can have loads of affiliates sign up to your site and have them automatically get their affiliate links with the proper 12345555.com/tubepage.php?aff=xxxx

Or you could setup a campaign with a tracker, I'm using bemob as an example to track your cpa.



Give a unique tracking URL to the affiliates you will want to promote your offer.

Aff 4321
trackinglink/go/ffdsadfsafsad54?aff=4321

Aff 4322
trackinglink/go/ffdsadfsafsad54?aff=4322

and so on.

Be sure to add your conversion pixel on your thank you page, and note that your affiliates will not be able to see their reports this way. Unless they are passing a unique click id and you are able to provide them a weekly report of their converted click ids.

Example of this,
Aff 4322
trackinglink/go/ffdsadfsafsad54?aff=4322&sub=unique-click-id

[Sorry for the duplicate post; this was written hours ago, and WF is not responding well today.]

The short answer is yes, although you need to accept that nothing will be 100% foolproof. (e.g., Someone could pass garbage in that aff parameter, and you wouldn't have any way to "fix" it.) In PHP, you would place the following wherever you want the aff parameter expanded:
(Something very odd with WF is not allowing this to be posted with the above line presented correctly, so you'll have to remove some spaces to get it to actually work.)

I don't know offhand how to do this in WP, but I'm sure there's a way to configure arbitrary PHP code, and there's also likely something in WP itself to insert the value of a passed parameter like this.