Hiring Paid Lead Gen Service

[Daniel Mcgonagle]

Hi all, first post here.  I've been approached by several lead gen gurus, and people offering actual services...

What's a standard fee or model successful WHOLESALERS are following?

Ad spend plus retainer?

Ad spend plus some other fee

Ad spend plus monthly fee no matter how much ads are?

Any contractual obligations?

Any recommended services?

Thanks in advance

Dan