We do a lot of user testing here at Evantage. A typical project can have a few rounds of testing. It’s that love of creative solutions for complex problems that leads us to find out if users totally get it or if they are struggling to complete a task we had all high-fived over when the prototype was initially designed. Lots of user testing ensures that we are certain that users will spend time on the site/application/device and find everything they need.
Performing all this testing requires users. Depending on the number of personas or profiles I create for a client this could be anywhere from 7-20 people for each round of testing. This doesn’t seem like much and clients often think that they can save the recruiting costs if they do it internally, but I find that hiring a recruiting agency to find users is more efficient and even cost effective in the long run.