Another crowdfunded start-up closes.

(This post originally appeared on The Washington Post)

Crowdfunding can be a great way for start-ups and inventors to raise money. Smart watch maker Pebble, music service Bitvore and virtual reality headset maker Oculus Rift all got their start by raising millions in successful crowdfunding campaigns. But be careful. A successful crowdfunding project does not necessarily guarantee future success for your company – or rewards for customers.

That was made evident just his past week by Kanoa, a San Francisco-based company that promised state-of-the-art wireless, Bluetooth-enabled headphones back in 2015. The Mercury News reported that at the time, the company said users would be “able to control how much ambient sound the earphones let in” and “block out the outside world” if they so desired. Unfortunately, these promises were made before Apple moved to dominate the market for wireless earphones with the introduction of Air Pods shortly after Kanoa launched. Timing is everything, isn’t it?

Kanoa ultimately shut down its operation, telling funders it would be unable to fulfill any pre-orders and leaving scores of customers who paid anywhere upwards of $150 for the earphones out of pocket.

Kanoa is hardly the first crowdfunded start-up to stumble. Last year another start-up–motorcycle helmet maker Skully–shut its doors and this past February a crowdfunded robotics company filed for bankruptcy.

Crowdfunding remains a great way for small businesses to raise money, as long as customers know the risks before they buy.