- don't do anything that is based on user-generated content(email, social network, ...)
- it cannot be anything the customer can make himself on his own(e-commerce website with woocommerce, payments with stripe, data storage with s3 ...)
- a NEW idea must be monetizable from the get-go to avoid big players coming in and taking over in shorter time than it takes you to get up and running and building a customer base
- it must be a new idea that has no market yet or existing players have insufficient offering
- if you cannot draw the idea on one A4 paper, the idea is too complicated
- if the price of switching providers is too low, you will lose customers when new players come in and vice versa if you are entering existing market
- if you cannot put out MVP in three months, the idea is too complex
- if the MVP(or even production version) software product/service cannot run on one single VPS or bare-metal server, it is way too complex
- if implementing gdpr and alike are too complicated, the idea is too complicated
- you should avoid storage of any user-generated sensitive information(invoices, payment/transaction details, passwords, keys...), sooner or later it will bite you in the ass
I have recently talked about the world of startups being done for since many large companies offer services for free, even if it is not their core business, they prevent new players form entering the market and pump up their stock by adding value to their name. If you have something new, the big players can take over the entire market whenever they want. Doing something simple worked in 2000s but nowadays a single developer cannot do what was passible back then and you need a team, and as mentioned above, massive financing to be fast to market. So essentially the world belogns to large corporations these days :(