Below are notes from my workshop at the Quantified Self 2017 conference in Amsterdam. Thanks to everyone who participated in the workshop!
These are some criteria I use when determining whether a tool will actually be useful to me, and whether I want to invest money and time in the product.
How much active effort does it take to use? On a scale of:
Once you determine the level of effort the tool requires, ask yourself whether you are willing to put in that effort. Sometimes the value of a tool is high enough that you're willing to go to great lengths to use the tool.
How does the device sync? Does it require that a company run servers? Does the device download directly to your own computer?
For example, the Withings scale only talks to the Withings servers. You can download the data from their servers later.
The Eye-Fi card can download directly from the card to your computer, which doesn't require a third party service to be running in order for the device to work.
What kind of export options are available from the tool? Planning on the service at some point shutting down or planning on moving to a new tool later will mean you will want to choose a tool that ranks higher on this list.
There are several ways tools make money, and you should be aware of the profit motive of any tool you use. There is no "right answer" and no "wrong answer" for whether you should use a tool based on this, but it's important to be aware of.
Did you pay just one time to buy a device?
Are you paying a monthly subscription?
Is the company making money off your data?
For portable devices, battery life is often a huge concern. People often have different preferences for this as well. Some people are willing to charge a device every night, others want to not think about it for months.
My FitBit battery lasts around 5-7 days. That's enough to go out of town for the weekend and not worry about bringing my charger. I also can't charge my FitBit at night, since I wear it to track my sleep.
Related to battery life is what connector the device uses to charge. Is it a proprietary connector? That's usually less ideal since it can be more expensive to replace, and is harder to borrow chargers if you need. Thankfully most devices are moving towards charging via Micro USB or USB-C, so it's usually not too hard to find connectors.
Another thing to keep in mind is whether the tool you're considering has competition in the market. Are there other options you can switch to if this service shuts down, or if your device breaks?
Are there other services that provide this or similar functionality? If not, you might end up "stuck" as a customer, and the company will have little incentive to improve things or reduce costs.
What will happen to the device if the company shuts down?
A Jawbone UP is completely tied to the company existing. The band has no interface, and requires syncing with their iOS or Android app to continue working. If the company shuts down their servers and unpublishes the app from the stores, the device will be nothing more than a decorative bracelet.
A Withings scale will still be a scale if the servers shut down, since it actually has a visual display on the device.