A free option might not even be necessary, just a "See how it works" page would probably suffice. Take us through a common use case, maybe even use that convention scenario I saw in Saaspire's blog. Take a picture at a convention, upload it to ThingCounter and ask us to count heads, we get back to you with a count of heads.

A video would be even better. Videos are very easy to consume, and it is typically very easy to win people over with a well-done video.

I found a little info on Saaspire's blog. [1]

Here's a relevant experpt:

> Sean gives a lot of his time towards helping to organize the local developer community and in particular gets involved with running conferences like DjangoCon. One of the problems he encounters as an organizer is figuring out how well different talks, activities, and events at a conference are performing. Basically, he needed a somewhat accurate idea of how many people were involved and didn’t want to have to do manual counts everywhere. His solution was to provide a service that allowed you to upload a photo and get back a count for the number of people in it. When he shared this idea with me, I thought there might be even broader applications for counting anything (e.g. marketing agencies needing to count SKUs on a shelf or biologists counting birds in flocks). Enter thing counter, a service that lets you upload a photo and request a count of something.

Sounds like you're paying to have someone count the number of X's in your photo.

[1] http://saaspire.com/blog/2012/8/our-lean-product-experiments