Adblock Stick

Ad blocking is fairly mainstream these days but I've never seen (or even really considered it could be done) it in this format. The marketing material is unsurprisingly light on technical details but, assuming this is real, possibly it installs itself as a network device and filters DNS queries similar to Pi-Hole..?

What confuses me is that, surely you could achieve the same outcome using software with very little overhead. Doing so saves all the manufacturing and distribution costs so you'd expect it would be a more profitable approach. So why the stick? Is the filtering overhead large enough to justify a dedicated co-processor or is the form factor used here really a placebo? In the way that a heavier wrist watch feels more valuable, does plugging a physical device into your computer to protect it/make it faster, _feel_ more effective than installing software that does the same job?