The Isolator: the latest rip-off?

Back in the 60's, people used to add mass to their tonearms by using scotch tape to attach a penny to the headshell. I saw many a Garrard, Dual and BSR table in college dorm rooms with this. Then in the 70's, Ivor Tiefenbrun of a new company called Linn, and others, demonstrated the importance of the source in music reproduction. Prior to that, emphasis was largely on the speaker. Given that record groove information is measured in the billionth of inches, I don't think that many turntable/tonearm designers thought it was a good idea for the headshell to be loaded with weight which would mask subtle groove information. Since then, what has changed in the physics what is happening that would lead people today to suggest adding mass to a tonearm?

I don't even know what this thing is, but even if the parts only cost 5 cents, if the guy spent an hour putting it together and add in the time and materials for packaging and shipping and the time and cost of marketing and some profit AND it is effective; then in the overall scheme of things $150 is a bargain.

BTW what is it?

"Snake Oil, Ya'll" Steven Earle

Regarding price, remember it is imported and has the importers mark up added as well. To me, the main point about an accessory is does it work. If $150 materially improves the sound of a $10000 vinyl rig, surely it is money well spent. I note some of the replies have suggested a real improvment.
I tried a number of CD improvement mats over the years, Ringmat/Blacklight, I could'nt hear a thing. Being a sucker for strong reviews, I tried the much more expensive Marigo Stealth Signature. Result, a clear improvement in the sound and that is what matters.