Can a social-media post demonstrating a technology be used to establish patent priority?

This post is based on my answer to a question on Quora. The question further asked whether there is any precedent for the legal use of a ‘first reported online publication date’ in social media to establish priority of invention for the purpose of getting a patent at a later time. my answer: No, this will accomplish exactly the opposite of what you hope to achieve. The only way to establish a priority date that will be meaningful for the purposes of getting a patent is to file a patent application. That patent application can be provisional or non-provisional. The question details assume that the social media post itself will somehow be proof that the author invented something as-of a particular date. The current US patent system doesn’t work that way. It has never worked that way outside of the US, and in fact, even under the US’s old “first-to-invent” rules, a social media or other online post would have been of very limited value. Instead of establishing a provable priority date, the post will become prior art that will prevent you from getting a patent in many countries (e.g., Europe). In other countries (like the US) it will start a clock for a date by which you must file a patent application in order for the post to not count as prior art. All this without providing any benefit in terms of establishing a priority date. If you’re not ready to file a provisional patent application yet, then the best alternative is to keep the invention a secret until you either file a patent application or you decide that you don’t need a patent....

What is the cost for filing an international patent?

There is no such thing as an international patent, so it is necessary to file national patent applications in each country in which you eventually want a patent. It is possible to delay  the date on which you have to file those national patent applications by using the PCT system. A patent application filed under the Patent Cooperation Treaty PCT basically acts as an international placeholder. A PCT application can claim priority to an earlier-filed national application. National applications must be filed within 30 or 31 months (depending on the country) of the PCT application’s priority date to get the benefit of the priority date. As for cost, it depends entirely on how many and which countries you want a patent in. I usually tell clients to budget somewhere in the ballpark of $50,000 (US) for a set of national filings. Sometimes it can be much lower (e.g., $10K to $30K), depending on which countries you file in. The largest part of the cost tends to be the translations. But that’s just the start, since most countries will also conduct prosecution of your application, so over time you will likely see prosecution fees of ~$10,000 to $20,000 per country, plus each country will also charge “annuity fees” (also called “maintenance fees.”), which will run another few thousand dollars per year (annuities get increasingly more expensive over time, since most countries use a rising fee schedule). So, it’s not cheap. You’ll want to be earning revenue from your invention (or at least well on your way there) once you start spending money on national patents. As mentioned above, the PCT system...