What Not To Build
In our startup ecosystem, we often see founders working on ideas that are extremely difficult to implement, so-called "tarpit" ideas. Tarpit ideas usually deal with solving obvious problems that surround us and at first glance seem great and straightforward, but hide deeper, not-so-obvious challenges.
To help the community avoid such ideas, we have created a "What not to build" list of examples of startup ideas that are extremely difficult to implement. Solutions that target these industries and areas are widespread, the market is mostly oversaturated, or the model has been shown not to work in practice.
*Disclaimer: Some of these ideas can be run as small businesses, but are nearly impossible to scale, making them bad startup ideas.
Who is this List for?
If you're thinking about starting a startup or considering a pivot, knowing what not to build is as important as finding a good idea. Many ideas may seem exciting, but are actually pitfalls behind oversaturated markets, intractable problems, or things people say they want but aren't willing to pay for.
We made this list for all those who want to start or have started a startup, to avoid common mistakes and focus energy on ideas that have market potential and the possibility of growth.
List of global tarpit ideas and why they fail
These ideas are almost impossible to succeed with, because they require exceptional execution, deep insight, and often a lot of capital to overcome inherent barriers. Many of them are very hard to scale cause they have dense global competition.
Social Platforms
Examples:
Eventbrite for Serbia with a better UI
Nightlife in Belgrade/Serbia
Aggregator of cultural events
Restaurant/cafe reservation platform
Why it's a tarpit:
The real value is in the activation of people, not in the platform itself, so technological solutions are mostly irrelevant.
Most users don't want to pay because free tools like Meetup/Luma or chat/social media groups already meet basic needs.
Without active users, the platform seems empty, and users will not come without activity.
Maintaining the platform requires constant moderation, creating and collecting content manually, which is challenging to scale.
Applications for urban efficiency
Examples:
Food delivery platforms
Parking applications
Applications for reporting problems
Why it's a tarpit:
The real value is in the activation of people, not in the platform itself, so technological solutions are mostly irrelevant.
Most users don't want to pay because free tools like Meetup/Luma or chat/social media groups already meet basic needs.
Without active users, the platform seems empty, and users will not come without activity.
Maintaining the platform requires constant moderation, creating and collecting content manually, which is challenging to scale.
HR platforms
Examples:
Tinder for jobs
Human Resource Information Platform (HRIS)
Online business board
Referral platform
Why it's a tarpit:
HR solutions are difficult to monetize because most HR teams have limited budgets and rarely invest in new tools without clear proof of value.
It isn't easy to make a difference in a market that is already dominated by platforms like LinkedIn, Infostud, etc. Both talent and employers already use them by default.
Marketplace models are difficult to grow; without a strong brand or niche, it is difficult to attract quality candidates and companies.
HR departments prefer platforms that already have a large audience and integrations with their existing software.
It's hard to monetize because users expect free access, while companies often don't see enough value to pay, especially in smaller markets.
Tourist platforms for local destinations
Examples:
TripAdvisor for the Serbian market
Aggregator of tourist tours
Why it's a tarpit:
Tourists already use Booking, Airbnb, and Google Maps, and it is difficult to convince them to download or trust a new local app.
Locals don't need platforms to discover destinations because they rely on recommendations.
Competing in SEO or user experience is almost impossible without a big budget, because you're up against deep-pocketed global giants with a long tradition.
Income requires a large number of users or partnerships, margins are small, and user loyalty is low.
Marketplace for X
Examples:
A platform for the exchange of used clothing
A platform for finding masters
Platform for scheduling hairdressers/beauticians
Marketplace for renting things
Why is tarpit:
You face a double problem because you need to ensure both supply and demand, which the larger platforms already have.
Users often bypass the platform after connecting, which destroys monetization.
Trust building, fraud prevention, and quality control are difficult to automate and require constant monitoring.
Operational burdens like payments, onboarding new users, and support cannot be easily scaled or automated early on.
How do you judge if your idea is a tarpit?
If the total market is only the Balkans, it is too small to build a startup.
If the solution depends on public infrastructure, tenders, or cooperation with the state, it will progress too slowly to survive.
If people are already solving a problem via Viber, Facebook, or Excel, they are unlikely to change their habits.
If you have to educate every user or partner to use the product personally, you won't be able to scale.
If the product needs to "go viral" because there is no other acquisition model, the idea is not sustainable.
If the main advantage is "better design" compared to existing players already in the market, you will quickly be copied or ignored (because it is not a relevant shift).
Why did we make this list?
Through working on ecosystem development, we've noticed patterns that slow startup progress. Teams repeatedly work on similar solutions to local problems without real user interest, often inspired by outdated trends from more mature markets. Such products find it difficult to achieve product-market fit, and even more difficult to attract investors and scale outside the local context.
We believe that our founders have the capacity for much more. By highlighting challenges and directing attention to global problems and emerging innovations (Request for Startups), we want to help teams build competitive, sustainable startups that have high potential in the global market.
Famous tarpit stories
This should not discourage you - many have started with similar ideas. This does not mean that they thought poorly, but that there is a serious reason why those ideas did not take off and why others abandoned them. Here are some examples of famous teams that worked on tarpit ideas but successfully abandoned them and pivoted into much more successful stories:
Slack
The team was working on a game that didn't take off, but in the process, they developed an internal chat tool that turned out to be much more valuable. They pivoted to the development of that tool, which became Slack. Salesforce later bought them for $27.7 billion.
Brex
Developing a VR product in the early days, founders couldn't find PMF. In the process, they noticed a lack of tools for corporate cards and finance for startups. They pivoted and created Brex, which today is a fintech giant worth over $12 billion.
Youtube
YouTube was initially launched as a video dating platform, but users started uploading all kinds of clips beyond its original purpose. The founders pivoted to sharing video content, and that's how YouTube was born. A year and a half later, Google bought them for $1.65 billion.