This looks quite nice and I do like the 'simplicity' of the interface.
One of the issues I've come across is the different uses people may have for this. A home inventory could be a 'simple' list of objects to one person, but to another they might want to have a number of bits of metadata for the item. For instance, a TV might have a number of HDMI ports, has a resolution etc. It might be worth looking at ways to add custom fields to items, either from a template or manually for each item.
I'd also suggest looking at how you can expose a log of who looked at what, when. Including on the database side of things. As someone else pointed out this is a gold mine of information for anyone nefarious, or an advertiser.
One thing I worked on for my project (which I'm not sure i'll ever get round to finishing) was a way to have a label that matched up with an entry on the site. QR Codes are 'ugly' but can work quite well for this. A short domain + a non base10 number for ID and you're off to the races.
A potential way to monetise this might be to work with insurers, I dont know much about the insurance market, but I'd assume they'd love to be able to put actual values and the like on someones household goods. Perhaps theres an avenue that insurers offset, or indeed pay outright, for users that meet certain criteria. Theres some prescience set for this in the UK with LeakBot, a number of insurers will offer customers this for free, as they are able to get information about a leak from that system. I'm not sure if it's shared with the insurer or not, but its something to explore as a possible revenue stream.