I'm talking about a series that will come from a squeeze page to buy a specific product...For example, someone goes to a squeeze page for a dog training course, signs up and gets a free report on dog training, and then is on the hook for a series of emails that will then offer dog training tips and try to get the prospect to buy the training course.
I'm sure it depends on niche. But is there a general rule of thumb where interest drops off and people start opting out? I can't imagine getting hit with 30 emails to buy the same dog training video (or dating product or weight loss tips, etc)...But there must be some general guidelines?
I feel like everyone knows this but me, LOL...I did do a post search and came up with nothing.