I wasn't sure directly replying by email worked, but I'm trying that now. (And... the email bounces. Fighting with the web page directly again instead.)

Yes, the activation discount is from opening the account online.

The due date is indeed 8/12. Furthermore, I notice in the pdf that although the bill period is 7/19 - 7/20, the plan charges are listed as covering 7/21 - 8/20. This is in-line with the explanation I found on this page:

https://www.verizon.com/support/view-bill-online-faqs/?adobe_mc=MCMID%3D3351842473047383142411278026...

I don't know if this always happens for new customers, but the bill cycle does align with the start of my service, so that the first bill is only charging me for one month's usage.

Thanks for the info that the discount takes a few months to apply. That seems kinda sketchy but it's not really any worse than the "Federal" fees that are Verizon charges and not taxes. I'm just glad to not be paying a full extra month's worth of surprise fees.

Lessons learned from my perspective:

1. Phone support lacks the communication skills to answer technical billing questions. Verizon's written policies are more reliable, at least when you can actually access them and not get http errors.

2. This forum has knowledgeable users, though the official Verizon accounts may be bots.

3. Always ignore the bill estimate and wait for the real bill. (FWIW, I ported this number from my mother's AT&T plan, and the resulting AT&T's bill estimates are also nonsense that the phone reps tell you to ignore.)

4. There is no "deposit" for the plan charges. Plan charges are generally prepaid (despite it being called a "postpaid" service), except that the first bill will include prorated charges for the initial partial cycle, if any.