Yes, this does use quite a bit of RAM.
Some things I've noticed so far:
This will not work if you've sandboxed your browser with Sandboxie. I'm not that interested in giving Breadcrumbs resource access because I don't think it's anything I'll use in the long run.
If you're using AdBlock Plus with the EasyPrivacy filter subscription, it's not going to find anything to block. At least I've spent the morning going to various abundant ad and tracker websites and I've yet to see anything in the watchers analytic panel. It is working though, because if I disable ABP, I see various trackers.
Its blocker is a bit crude. Blocking the BuzzFeed 'watcher' across all domains will block access to buzzfeed.com. Same for similar 'watchers' such as twitter and facebook. In other words, it lists links to some sites as a 'watcher'. If you just assume everything in the watcher list is a tracker, you're in for a surprise as not only are some links in the list, but also CDN servers. If you block these, you'll wonder why you're unable to view some site content. The application doesn't give you any info on these watchers either, so you can't make an informed decision. For example, clicking the link to give you more data on GoogleAnalytics comes up as a failed search on the Breadcrumbs site. They don't have any info on GoogleAnalytics?
It does generate some interesting data about the 'watchers' you encounter or block. Numbers such as the percentage of websites you've visited that contain a particular watcher.
So for me, really the only thing this application has going for it as far as my situation goes, is this 'Bogus Identity' thing. I've yet to see that do anything yet, but that could be because it's supposed to do its thing when you aren't browsing, and I've been browsing like a madman while seeing how the tracker blocking works. Or perhaps it it parses your browsing history to decide what sort of sites you visit regularly, and since Sandboxie auto-deletes my browser data, there is nothing in my history for it to look at.
I'm also a bit on the fence whether or not this bogus identity is even a sound concept.
Anyway, I think I'll play with it some more.