As the title says, does all startups need investors?
What about web applications that are made by a colleague team with costs only the hosting server?
What If they have an office too, nothing too fancy, but ideal for the purpose of meetings?
I guess they need a big amount of money for advertising though, but what else?
What are some other reasons that finding money from investors is a must?
We can tend to get the idea from news reports and places like TechCrunch and Y Combinator that every startup has outside investor funding. But that is a misconception.
There are many successful businesses that don't have investors. In fact, if you can bootstrapp and build your company without one it is often better for the following reasons:
Note that You may be able to find advisors who can do this for you who do not have to be investors.
The only reason you really need an investor is:
Well it is a difficult question to answer and depends what business are you looking to establish.
Since my understanding is you would like to do something in the online space, I would say no. You don't necessarily need an investor to develop your product (website) and it cost little to host it on virtual servers. If it would be only you and your business partners working in your extra time for no salary, you won't have any real human capital expenses too.
So my answer is yes, you can incubate and seed your business without investor, but note it will be a hard work.
Growing your business without an investor might be a bit too difficult however, since as your site grows you would need to invest more into servers, hire people to take care of technical or commercial side etc. and co-funding this from your cash-flow in the early stages might be close to impossible, unless you start something absolutely fantastic that would be a massive hit from the day 1.
The issue is one of planning. First, figure out where you want to go and go from there.
If you see that you need to spend $100,000 on marketing and the founder don't have or don't want to put that in, then you need an investor (or investors).
There are many places to spend money: operating expenses (servers, hosting, office space, salaries, etc.), marketing (advertising, promos, etc.), and even finance (servicing your debt, etc.). Before you start to look for an investor, make sure you need one.
In general startups do get some sort of investment because funding growth through profits is very difficult unless you have a surprisingly profitable startup.