Just because you have a great idea doesn’t mean your startup will succeed, and there’s a simple reason for this: concepts don’t make companies.

Startups depend on everything from the capabilities of their founders to the depth of their pockets. But, just because an idea hasn’t taken off doesn’t mean it won’t eventually, right?

Particularly in the tech scene, you’ll see ideas tried countless times before a true winner emerges. Let’s take a look at 10 startup ideas that haven’t broken through just yet, and see if there’s a pattern.

1. Group Photo Sharing

Group photo sharing startups have become so common that some of us at TNW created Gmail filters to weed them out of our inboxes. Some noteworthy attempts to master this concept include Adobe’s GroupPixColor, SwirlPinweelClusterAlbumaticTracksYogileFlock, Google + Party Mode, and CapsuleCam. Still, even if it’s not a pressing issue, sharing memories back and forth with the people you love is often difficult, and it would be nice if a service emerged to make that easier. We’ll see if that happens.

2. Location-based Social Networks

Highlight, Banjo and Sonar are the three biggest players attempting to make proximity-focused social networks happen. People get lonely, and connecting someone with potential friends nearby is an excellent idea that has yet to find widespread adoption. It is noteworthy, however, that startups like Tinder have made waves doing this within a particular niche.

3. Replacing Email

Everyone hates email, and yet nobody can live without it. Google tried to replace traditional email with Wave, others, like Kukoo and Dispatch, are augmenting it to make it easier to live with. All the while, my inbox overflows (:cries:).

4. The Digital Business Card

If everyone just picked one digital-business-card-service and stuck with it, we would never need to print wasteful business cards again. Unfortunately, that has yet to happen. Standards aren’t followed, and everyone still uses cards to share their emails (which are then added to an address book, while the card is thrown away).

5. The Digital Loyalty Card

Sitting nicely alongside the business card killer, the digital loyalty card is a great idea. Keeping loyalty or punch cards for every restaurant you visit just isn’t practical. Unfortunately, there are enough small players in this space to keep it annoyingly fragmented. Nobody wants to replace 10 loyalty cards with 10 different apps.

6. Social Ecommerce

Shopping AFK is a very social experience. So why, an intelligent person might ask, are we shopping online all alone? Companies like Fancy are arguably succeeding at something close to this idea, but the social pastime of shopping with your buddies has no digital equivalent (yet).

7. Social Address Book

This may be a perfect example of the “feature not a startup” debate. Many have tried to create a true social address book, including the likes of Brewster, Everyme and Addappt, but none have managed to replace default smartphone address book apps for the majority.

8. Killing Craigslist

Craigslist, in all its ugliness, just won’t die. Believe it or not, it’s still one of the best ways to look for apartments, sell furniture and find jobs nearby. There’s reason to believe a more suitable replacement will emerge, but unfortunately it doesn’t look like designing a slick UI with similar features will make that happen.

9. Social Recruitment

Job sites that attempt to tap into your social networks are exploding. Companies fighting for your attention include Path.To, Bright, Slip and Tribehired. Still, this idea has yet to truly shine, aside from serving as a handy feature for LinkedIn.

These ideas are up for grabs if you’re willing to give them a try, but be sure to learn from the mistakes of others before you take on the challenge. If we missed something, be sure to let us know in the comments below.

Update: Sorry folks, looks like we got a little carried away and listed nine rather than the 10 concepts that the original headline reflected. If you’ve an area that we missed, we’d be happy to add that to make it up to 10.

Image credit: Thinkstock