First to market instead of Patent application

If you are sure that you never want to patent your invention, bringing it to market prior to anyone filing a patent application on the same invention should enable you to later invalidate their patent should it issue. The keys are that you need to publicly disclose the invention prior to anyone filing a patent application and you need to be able to prove WHEN you disclosed it. Therefore, it may be best to disclose the information as soon as possible in a press release so you can prove the time and date of your disclosure.

No! Quite the opposite. When you bring it to market, you're making a public disclosure. Now, you can protect the inner workings, etc. as a trade secret (like Coca-Cola's ingredients), but you can't patent something disclosed. If what you have is likely patentable, file a provisional patent (which is not examined and not publicly disclosed) at least. That will give you 12 months to decide whether to file a utility patent (which will actually get examined). During that time, you can bring your product out. Don't disclose the provisional to anyone without an NDA. This is a cheap, cost-effective way to keep your options open for another 12 months.

One other point: If someone tries to patent what is your product, you'd be able to stop them by showing that prior art existed. But you still wouldn't get a patent yourself -- drum roll -- unless you were the inventor and the disclosure was within 12 months of the filing (there's an exception for that). Be safe. File first.

FYI, the USPTO's own language governing this states:

"In order for an invention to be patentable it must be new as defined in the patent law, which provides that an invention cannot be patented if:

“(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention” or

“(2) the claimed invention was described in a patent issued [by the U.S.] or in an application for patent published or deemed published [by the U.S.], in which the patent or application, as the case may be, names another inventor and was effectively filed before the effective filing date of the claimed invention.”

There are certain limited patent law exceptions to patent prohibitions (1) and (2) above. Notably, an exception may apply to a “disclosure made 1 year or less before the effective filing date of the claimed invention,” but only if “the disclosure was made by the inventor or joint inventor or by another who obtained the subject matter disclosed… from the inventor or a joint inventor.”

In patent prohibition (1), the term “otherwise available to the public” refers to other types of disclosures of the claimed invention such as, for example, an oral presentation at a scientific meeting, a demonstration at a trade show, a lecture or speech, a statement made on a radio talk show, a YouTube™ video, or a website or other on-line material."

No - only a patent provides you with the right to prevent others from making, using, or selling your (patented) invention. By going to market first, you commit two possible fatal errors - one, you may destroy your right to get a patent, particularly outside of the US if you eventually want to patent the technology in Europe, Asia, wherever; and 2) by marketing your invention, you may in fact infringe someone else's patent - remember, someone else might have a patent which gives them the right to prevent others (you) from making, using, or selling their patented invention.