General overview of what's going on with paypal. Their policies are subject to change at any time after I post this. I just want to help keep people's accounts safe <3 If you're gonna be all "MEH I DON'T BELIEVE U!!!" Then just call paypal yourself to confirm it.
Paypal is not out to get you. As long as you abide by their AUP, you will not get in trouble.
As long as you are sending your commission payments as "For Goods and Services" you will not get in trouble. [and of course, as long as you don't mention if the payment is for anything nsfw]
If you want, you can either copy/pasta this journal or you can just share the link.

What is it?
Paypal will be updating it's policies.This includes a $2,500.00 fine if they catch you breaking their Acceptable Use Policy. (because most sites have this in order for you to use them, surprise!) This will go into effect on July 1, 2015.
They can also close your account, hold your balance, suspend you from using paypal in the future, and take other legal action.

Why are they fining us for breaking their AUP??
Because breaking rules sort of has consequences, especially when you are essentially stealing money from them while they provide you with a easy-to-use service. They are also dealing with people much bigger than artists that are repeatedly breaking their AUP and they have to scare them off a little with a big fine.
It has always been against their AUP to skirt around fines, but now they are getting tired of it, and rightfully so.

Why are you telling us this?
Because when you send commission payments as "gifts" to get around Paypal's fees, you are essentially committing small fraud. Which is illegal. Which violates Paypal's AUP. If they catch you, then they can fine you $2,500.00 per violation starting July 1, 2015 (among other things like locking your account and keeping you from using paypal in the future, taking legal action, etc.). I personally called Paypal to confirm this, you can too if you want. [go to 'contact us' on Paypal's website]
Fraud is the deliberate deception to secure unfair or unlawful gain. So basically by deliberately skirting the fees, you are committing fraud. Please don't do this.

HOW DO THEY KNOW???
Because when an account is given multiple "gifts", then it's pretty much reason for suspicion and they will most likely investigate. And yes, they are allowed to investigate anything that might violate their AUP. Also, if a commissioner sends payment and puts anything about "commission" or "artwork" in the payment, then it's a dead giveaway that you are trying to get around the fees.
They will not get you for a single transaction. You have to be making multiple ones to raise suspicion. But honestly? Just stop being a cheapskate and use their services the way they are supposed to be used and you'll have no worry at all! (honestly, it's just a few dollars)

How can I avoid this?
Abide by their AUP and just send commission payments as "For Goods and Services" instead of being a little buttfuck and trying to get around the fees. It's not worth the risk and Paypal takes a very small fee. Adjust your prices to deal with the fee so you still get what you need. [I honestly don't have a problem with the fees]
Do not accept payments that are sent as "gifts". Tell your commissioners to send them as "for goods and services."

ARTISTS: Send invoices. Here is a tutorial on how to do that properly. These are amazing little things and help you stay organized <3

Commissioners: do not send your payments as gifts. This risks your account and your artists. If your artists asks for it to be sent as a gift, then please let them know of the AUP or send enough to cover the small fee.

But what if I am sending a legit gift or tip??
as long as you aren't sending legitimate gifts too often, you should be ok. Or using a person's "donate" button will help too. I would ask about this though, as I am not 100% sure.
Tips, however, as long as it's actually a tip, you can probably just put "a tip for your hard work, thank you!" in the payment notes and you SHOULD be ok. Just don't abuse it.

I'm not gonna do this, I don't believe you
That's fine. You aren't obligated to believe me.

If you need any help understanding any of this, please let me know and I'll do my best to help you.

They also aren't going to get you for a few "gift" transactions here and there. As long as you aren't doing enough to raise suspicion. But honestly, it's just better for you if you just send it as "goods and services."
And selling porn is against their AUP anyways, but just make sure not to mention anything NSFW while making invoices/sending payments and you should be fine.

I literally called paypal and said "so it's against your AUP to pay for goods/services by using the gift option to send payment instead to get around the fees, correct?" "yes ma'am. That's fraud. Depending on the amount, we may or may not report it to the IRS, but we will fine and take other actions if we catch it happening." "HA I KNEW IT. THANK YOU. NO ONE BELIEVED ME." and then the lady laughed.