For example, to keep track of products you add to your shopping cart on fitbit.com and improve our website’s load speed and performance.</p> <b>Analytics and Research</b> To help us understand how you are using the Services so that we can make them better, faster, and safer. <b>Advertising</b> To enable our partners to serve ads for our products and services. deliver relevant ads to people who may be interested in them on other services. measure the performance of ads. and opt you out of receiving interest-based ads if that is your choice. <p>