So...is upgrading of hotel rooms totally random or based on the customer?

[spudcounter]

you know when hotels upgrade you at reception..what influences their decision to do this? Is there anything I can do to increase my chances of an upgrade?

book for a Friday/Sat if it's in a business district, eg The City. If it's wedding anniversary etc, mention it on booking. Be polite, look smart. All increase your chances ime. I've been upgraded several times recent;y.

If a chain be a member of their loyalty scheme, you can join mist online.