You're really better off installing an affiliate script on your site, and then making the same offer.
Just making the offer the way you have it as now, means the person helping to drive traffic to your site would have to rely on you "keeping your word" and "being honest" (not to say you wouldn't do either of those things, but hopefully you see what I'm saying).
You could install an affiliate script that lets you designate commission amounts to pay out, then come back to BHW and say:
"I'm starting a business selling widgets. I've got an affiliate script set up at my site, and I need traffic driven to my site to generate sales.
For your first month as an affiliate, you'll receive a 50% commission on all sales you generate. After 30 days, the commission amount will drop to X%"
This way you get all the following benefits:
- The people sending traffic to your site will obviously only want to send targeted traffic.
- No bickering with somebody about "You're not being honest about sales volume!! I know my methods MUST have driven more traffic to your site than you're saying, and I know it HAD to have generated more sales!!"
- You don't end up paying somebody 50% when it may have actually been your marketing methods that produced more than 50% of the traffic and resulting sales.
- You can track where all traffic is coming from and see what works and what doesn't.
There are many benefits and really no drawbacks.