I think the referrals only didn't work for some people. I just checked mine, and it says @acidyo. So mine managed to work.
I don't really get why they wouldn't be able to script in a fix for anyone that wasn't referred correctly. The URL should be in the server logs. Well...if there server has logs... Okay...maybe they didn't set up their server to take a log of the incoming URL for some reason.
I agree with you about the spending in the beginning. Though now, after playing it for a bit, I wish I had thought more about the percentage with upgrades and focused more on the high level buildings. With battles disabled, now is the time to save up for the highest level buildings you can get, unless you do the math and figure a lower one will get you more upgrading now than waiting.
I know of 4 people (one of my alts) and 3 others who know for sure they used my referral and none of them showed up as a referral. The devs said this is a known problem and nothing they can do about it now but allow you to specifically choose a referral for a week.
It's hard to get some of the higher buildings without upgrading storage pretty high due to the caps, so if you are saving up make sure you check your storage limits, but you have at least 24-48 hours before you are at risk of an attack, so it's pretty safe to save up.
Keep in mind though today's daily is 5% heist and 5% daily, so depositing Drugs is five times more rewarding than normal.
Yeah, I have been upgrading my silos for when battles are re-enabled. Guess that's lucky, because the bigger building require HUGE amounts of resources.
Depositing drugs doesn't pay off that well compared with keeping them normally to upgrade a building, so I wonder how much it will help now with the bonus.