As per usual, it all depends.
For me I do a lot of research first, so by the time I set up the campaign I'm pretty confident it'll work out. It all depends on how much testing you're willing to do.
Personally I wouldn't test with just 1 offer, and give up on the campaign if it bombs.
Likewise I wouldn't test just direct link.
So test our 3 similar offers from the start - quite often I'll get one with get zero conversions but similar ones will be profitable.
Likewise 1 direct link and 2 landing page variations (which take very different approaches, not minor changes).
So:
- 2-5 times offer payout per keyword
- Start with 2 - 5 keywords
- 33% to each of - LP1, LP2, Direct Link
- Rotate ads evenly across a bunch of ads
Since you're doing different offers, this makes more work as you need separate campaigns for each (don't fuck it up by having company xyz in the ad text and the dest url go to company abc - then bitch and moan when you don't get paid)
If you're talking about Adwords - With a perfect QS you can decrease CPC in half hence the 2-5 times payout on the offer.
Plus after split testing your conversions can go up another few hundred %.
Thats just how I do things - if I get zero conversions on a low paying offer I often pull the plug a lot earlier.
But if you're getting back even 25% of your spend off the bat - it still has hope. Obviously I also spend more on testing on something that can potentially do huge volume. So it varies drastically.
Also - Rather than $100/per offer for testing - I'd adjust that based on the offer payout. If it's a free trial, thats not enough to test with, if its a low paying game - that's more than enough.