Personal projects often start out, understandably, with no regards for business legitimacy. As such, the productizability and/or monetizability of such a project is immediately suspect. Here are a few things I keep in mind when contemplating potential business strategies of personal projects.
the 'personal project <-> product' boundary is murky for many reasons. One big one is motivation. Products are made for profit. Maybe other reasons to, but always profit. It's essentially implied by the word "product". Personal projects, on the other hand, are made for basically any reason at all; curiosity, research, etc. This can lead to a misalignment in motivations that can itself lead to an unwittingly half-hearted pursuit of profit. If you aren't initally motivated by profit, you have to become motivated by profit. But, the profitability of your personal project might not be personally motivating. This can be particularly difficult to realize because you are motivated by your project's success in general, otherwise you wouldn't have made it, but "your projects success" might not be "your project as a product". Even worse, you might not observe this fact within yourself. Our society, and tech in particular, surrounds us with a false equivalence between success and profit, so the probability of subconcious conflation between the two is high. In brief, don't bait and switch yourself! You might not actually want to "defile" your project by turning it into a profit-making product.
Assuming you are an initial team size of one, you have no initial funding, nor are independently wealthy, and you are busy with your day job, I dare say you don't have the time or money to be competitive.
Competition implies (arguably) a saturated market. The problem with saturated markets is that differentiation from competitors is required. This can be approximated (arguably) as a need for a marketing team. The unfortunate and obvious truth is that you aren't a marketing team.
Even if we assume you have a superior product, you don't just need people to find you once. You need people to find you often. For example, you would want to constantly tweet from a business account so your early-adopters retweet, and their followers occasionally see it, and as such you enter their brand lexicon. And that isn't even the start of a sales/marketing funnel. There are automation tools to ease the time-cost of managing marketing, but in my opinion that drops the time-cost from extremely expensive to really expensive. In conclusion, you don't have time to be competitive.
Also, take a look at Ubersuggest (or any other keyword investigation tool) for keywords in your product space. Look at the SEO difficulty, paid difficulty, and CPC (cost per click). The more saturated the market, the more difficult it is to be found organically, and the more expensive it is to be found through ads. And once you are found you have mere seconds to convince someone to become an early adopter, which is something most people aren't interested in being to begin with. So, for a fraction of a fraction of people, you have seconds to convince them to try your product. But, that requires a lot of careful thought on a marketing/branding page which you might not have built yet anyways. In conclusion, you can't afford to be competitive.
If you begin a personal project in a space that already has a saturated market, and then try to productize that project, that is a yellow flag, in my opinion. It's not a red flag since you might have some sort of differentiation strategy. But it is a yellow flag, because it means you could have used one of the pre-existing products to accomplish your goals, and chose instead to build your own, which is a non-trivial commitment. I would surmise from this a complex motivational tapestry, and wonder how strong your profit motivation is as a result. In conclusion, I'd recommend you double-check your motivations.
If you pass all these checks, then you are faced with (what feels to me like) "the only option". I.e., you pivot your project into a particularly empty part of the product landscape, ensure you have a community that will give you money to solve their problems, fill that void, and monopolize that niche. The approximate notion of "find your monopoly" is definitely not my own idea, it is a well-touted strategy in the startup advice scene. I think I first came across this strategy in The Lean Startup, but don't quite remember.