If your carpet is newer and only has one or two visible spots, paying to clean the whole house does not make sense. The drink spot near the couch, the food mark by the table, the sun-hit spot you see every afternoon. Those can be handled in a quick visit for a lot less than a full cleaning.
Spot Cleaning works best when the carpet around the trouble area still looks clean to you. Once traffic lanes are dingy or pet areas are heavy, a full clean is the better deal. We will tell you on the phone which one fits your situation.
A lot of folks pair this with a future full clean. We treat the spot now to get rid of what is bothering you, and then put your house on the schedule for a full extraction once the rest of the carpet starts to need it.