I think it largely depends on what type of site you're asking to hunt. If it's someone's yard your chances aren't all that great. But if you ask to hunt a cultivated field (that's not planted) then your odds are very good. My technique for getting into fields works well since I live in a historic area. Basically I tell the owner that my hobby is researching old homes in such-and-such county, and I came arcoss some interesting info about their property. That almost always gets their attention. Then I discuss and present to them copies of my research materials (old maps, land patent info, aerial photos, old topos, etc), and they're almost always very appreciative. Then that's when I pop the question. But I first tell them that I'm interested in determining the exact location and age of the original homesite on their property, and I can do that by both eyeballing and performing a detecting survey. Its hard for them to say no since I've already given them some cool documentation. So far this season I've tried to get permission this way about 10-12 times, and have been successful in all but one. And that was when talking to an out-of-towner over the phone. I never mention about splitting finds, but if they bring up that topic I'll agree to put together a display case with some of the items found. I've given away quite a few of these over the years, and the owners are always thrilled to get them. And since someone else mentioned this, I do not like handing out my detecting business card unless asked (which is rare). Several times over the years when I used to provide my contact info it came back to bite me. What happens is that you get permission to come back later to hunt a site, but after the owner talks to other family members who don't want you there I'd get a call revoking my permission. Also, it always helps if you know a friend or relative of the property owner, and have them put in the request for you. A property owner is much more likely to give permission though someone they know and trust than to a complete stranger. Anyway, don't know if any of these techniques has an application for you, but they're definitely ones that have proven successful for me many times. Good luck!