I've gone thru Vanilla, Pink Pearl, and green Brown.
Vanilla took about 2 years. I used it as a highlighter and shadow, alot. Pink Pearl about a year, because I mix it with lip gloss constantly. It seems to take more product to mix it with other things, at least to get the intensity of color that you would want. Green Brown, I spilled half of it on the sink, so I guess it really doesn't count for using it completely. I put them all in sample jars now, so if I spill, it's not all gone.
Keep in mind, I'm not just using on myself. I used Vanilla on many a bridal party
For the average person, it would take a loooooong time to get thru an entire jar, especially if you have many to choose from.