I think it would really help for the amenity pack to include enough toiletries for a few days away in a hotel. Just about every hotel room comes with a shampoo and soap. However, very few come with things like deodorant, shaving gel, toothpaste (unless you call the front desk).
I've been putting together a travel pack of toiletries for my carry on bag, and its not that easy to get this sort of stuff. In the UK, a lot of chemists will stock travel sizes for toiletries in the summer, but not through the rest of the year. Superdrug does keep a wider range. However, the pack sizes tend to be ~ 25ml, which is enough for a fortnight, but overkill for a few days.
Deodorant is a particular problem. I've got some Nivea cream in a 35ml pot from eBay, but other than that the smallest, lightest packs have been 50ml roll ons. I've seen 15ml sticks of solid deodorant at
http://www.minimus.biz/ but they are based in the US.
For shaving, shaving oil comes in little bottles, but I also like to use a gel like the one from King of Shaves. The normal tubes of that are 175ml, so they wouldn't be allowed in a carry on bag in any case. You can get a sample pack of that once a year, but it would be nice to have a pack of the gel which is between 10 and 25ml. I bought an empty tube and filled it with the gel, but it would be really nice to not have to bother doing this.
Sometimes travel packs of toiletries come with grotty disposable razors, which are cheap and light, but horrible to use. It would be good to include a decent 3 blade razor, along with some sort of lightweight packaging to protect it from getting bashed. For instance, a Gillette Mach3 razor and blade weigh ~ 20g, whilst a Gillette Sensor 3 disposable is 5g.
Other things that might help, but that everyone might not want are: hand cream, sun screen, lip balm, mosquito repellant, antiseptic hand wash etc.
Virgin could make a point of putting together a pack of toiletries, in a transparent re-sealable transparent bag, which would weigh say 150g in total, and be enough to last for a short trip.
If someone is on a longer trip, and has brought more than that with them, they could keep it for another trip, perhaps if you're packing light for a trip with just carry on luggage, when there is a weight limit of 6 or 8kg. Virgin then gets their logo on display on another day. On the day you are flying, seeing the Virgin logo on a Snooze pack means nothing as you already see the logo everywhere on the plane.
You might give away a pack like this in Upper Class, but I would pay for something like it if I was in Economy, if the products were decent quality, and particularly if they would be easy to replace when they get used up.
A well-chosen pack of toiletries would be something that I would use far more often than I would use cuff links, or other trinkets like brushed aluminium business card holders.