GP: Guinea Pig
"Guinea Pigging" is a term used in online communities to refer to the act of being the first person to order a seller's product. This means you will be the first to receive the product and post pictures of it online, allowing the community to evaluate its quality. This can be a risky proposition, as the product may not be of good quality, but it helps inform the community and is appreciated by other members.
Here's an example of how "GP" can be used:
"Is anyone willing to GP Troy's V4's or Xiao Daniel's Gen 2's?" In this context, the person is asking if anyone is willing to be the first to order and review the quality of these products. This is a common request in online communities where people buy and sell replica or knock-off products.