Evidently for their trials, they have bots that scan the VMs and kill machines running cryptocurrency software. Just read a bit of threads on google, reddit about this.
Possibly, you can run it on paid machines - but why would you? They charge you more for a machine/hour than you can make cryptocurrency/hr.
If the free tier isn't funded by conversions, then it's only really valuable as a marketing tool.
This is why hosts are often judicious with the free hosting tier - even with address verification and capchas, 60% of the free tier is phishing hosts using a stolen identity and credit card. About 20% are Ebay snipers running shoe-bots, or crypto-miners, begging for bare metal for the response times or hardware, respectively. Another 18% are technology generalists who might cobble together a 2004-era blog hosting service, to engorge their inner nerd - mostly harmless, might not patch something, but will never convert.
For the first 2 groups - once the credit is up (or gets flagged for spam/phishing), the account gets flipped. The scammer uses new email and maybe a new credit card, and migrates their activities. Darknet forums (and probably some subreddits) have lists of providers and how to work the free tier. I expect software to auto-balance between multiple free-tier accounts on multiple cloud providers exists; I've debated scripting the API calls in Powershell in a few weekends.
Some shoes have limited editions where only a specific number of pairs are manufactured. e.g. Yeezy Boosts by Adidas. They are Kanye West's design and very exclusive. So when they go on sale they run out within seconds. Most of the people who buy them then put the up for auction on other sites like eBay where they can fetch up to 20 times the price.
So people who want them have to get them quick so they need automated scripts that can add to cart, fill in credit info and check out the moment they are released. (The manufacturer usually announces in advance exactly the date and time they will be released).
People pay a lot for these bots. I once wrote a bot for somebody off Craigslist for a certain clothing brand that was selling exclusive jackets and shirts like this. ( I do a lot of automation and scraping for my day to day work so it was not difficult). The guy paid me $600, didn't even try to negotiate downwards. The bot bought 10 items (max allowed in the cart) at like 250 each. I looked the items up on eBay sometime later and they were going for slightly above 1k. So I actually felt I could have asked for much more.
Anyway, long story short, people put a big value on exclusivity and brand so they are willing to go to lengths to secure these limited items.
It's an eBay bidding bot - bid on a popular product faster than humans. For some reason, shoes were extremely popular, and I have only ever seen this type of user target shoes, and not other products such as handbags or hats.
Actually it's mostly on niche stores that sell limited edition items like Yeezy Boosts, Supreme, BAPE. They even do it for clothes now. They have a release date and time and sell out within seconds
How is Etherium's latency? Would it be at all worthwhile to pursue building a shoe-bot (or other HFT/bidding bot) on an Etherium platform? Is there a future where users could pay more Gas to get a low-latency response?
Possibly, you can run it on paid machines - but why would you? They charge you more for a machine/hour than you can make cryptocurrency/hr.