What else can I use my small private proxy network for?

I have a handful of clients that I do some social media automation for and I generally setup a PC on-site to route all the traffic through. I'm in the process of swapping out those machines for raspberry pi's I'm setting up as proxy servers.

Once I have my little private proxy network of squeaky-clean IPs setup I was wondering what else I could use it for besides Instagram bots? I figure between existing clients and friends/family who will allow me to plug a raspberry pi into their home internet I should eventually have about 50 in total.

My first two ideas were shoes and tickets. Neither of which I've done before so no idea how well those methods are working at the moment.

Adidas proxies and wait for new yeezy drop. people will buy 100%