What these opportunities typically turn up to be is a pyramid scheme. You pay a fee to signup. You then receive a flyer saying how great stuffing envelopes is and list of names and addresses to mail said flyer. IF those people pay that signup fee so they can mail that flyer too, you get paid a small referral fee. ONLY if they take the bait do you get paid.
I’m a reference this blog post in a thread in the near future on DNN and recommend people visit your blog about making extra money in 2018. I’m really glad you mentioned this because you have a lot of interesting sites linked on here that I need to check out. I have some household items I need to sell and will look back at this post again momentarily. Thank you for just being you, Nick. :-)