yes, it took 3 calls from them to upgrade me as Elevate Gold from MC to MCS, but they said it was a "one time" courtesy upgrade in appreciation of my business

Some of this still just doesnt make sense, and the other posters are correct, the folks at the Gold desk dont seem to know what the rules are, policies, or how they work

And, if anyone can tell me where the "Opt In" check box is when booking a ticket, I would love to see it.

i have done sample bookings and I just dont see one. Anywhere.

It is the very last step. There is a small box on the bottom right under I believe the insurance section.

VX Comp Upgrades
 

Virgin America Gold and Silver elevate members are eligible for comp upgrades from Main Cabin(MC) to Main Cabin Select (MCS) subject to space availability.

There are two ways to get an upgrade.

The first is through the "Auto Upgrade" tool. When you book your ticket at virginamerica.com you can select to auto upgrade. If you do this, at 24 hours prior to departure the system may or may not select you for the upgrade (the algorithms the system uses are unknown). A word of caution: The system may put you into a middle seat. If you would prefer to keep your window/aisle seat in the MC rather than a middle seat in MCS, do not check the box for the auto upgrade, go to the airport instead.

The second, traditional, way to get the comp upgrade is to speak with a teammate at the airport ticket counter or gate. They will put you on the list for the comp upgrade and you can advise them at this time if you do/do not want a middle MCS seat. This standby list is assigned 30 minutes prior to departure, if there are still open seats. If you don't auto upgrade, you won't know until 30 minutes prior as VX tries to sell the upgrades first.

Hope this helps!

The above is not completely accurate. While you may end up in a middle seat the system does not assign the seat. You have to choose the seat from those remaining in MCS. The sooner you check on the upgrade, the more likely you will not end up in a middle seat. Getting it assigned at the airport almost guarantees a middle seat unless the flight is very empty.

If you wait until the airport to get on the list, the chance of an upgrade would be greatly diminished. Many people are being given gold/silver status through matches. All the gold and silvers already on the list may have been upgraded. Add in those that paid for an upgrade during online check in process, and the chances for an upgrade go down even more.

I guess you don't get upgrade to MCS if you use your points to book.

Some phone agents will list you if you call in

I called in and that's how I learned about it. Any tips on convincing?

I'd like to know this too. I only called once to the Gold line, but they reiterated several times that since I'm using award points to fly, they wouldn't let me upgrade to MCS. I also asked to speak to a supervisor who echoed those same thoughts. I didn't try again so it might be the luck of the draw. Still, i hope there's someone who was upgraded and purchased tix via award points.

I've called on award tickets and have been offered an upgrade to MCS, but without a seat assignment. Since there are few things I dread more than a middle seat, I declined.

Yesterday I checked in on the phone app to see if there were first class seats available for upgrade purchase exactly 24 hours before the flight. It offered MCS for $179 but F wasn't available. Just to make sure I called in the gold line to "upgrade to F." The rep apologized and said all the F seats were taken, but that since I'm Gold, I get MCS for free, and asked me which seat I wanted (without any suggestions from me - the rep just said it). I was ready to shell out the $179 so really lucked out by calling in to see.