I have been a paying member of eHarmony a couple of times. They match members with non-paying members who are unable to respond. From eHarmony's Q&A section:
Question: Are users required to post a photo?
Answer: eHarmony doesn't "force" our users to post their photos, and we wouldn't want to. We have promised to begin matching you as soon as you are accepted into our system, even before you have subscribed. This helps to demonstrate how we work, and is one of our most important methods of generating trust in our service.
More like one of their most important methods of generating revenue.
Before you pay, you are unable to see photos of "matches". The text which appears where a photo would be says,
"You must be a subscriber to view photos if posted. "
Be sure to read the last two words: IF POSTED. You are most likely to find no photos are posted even after paying to join. Of course, there is bogus spin about the insignificance of appearance. Here is more of the "answer" from the question about posting photos:
If posting a photograph were a prerequisite to completing the Relationship Questionnaire, this would exclude anyone who didn't have scanning equipment immediately on hand from joining eHarmony, severely limiting our membership. In fact, you may remember that we matched you before you had photos posted, and I'm sure you appreciate that we did not eliminate you from matching before you could amend this situation.
More like severely limiting their revenue! In fact, you were used by them to scam others into joining! At least the sort of acknowledge they are going to use you just like they use everyone else. It has been my experience that the only people who do not post photos are those most others would find unattractive and would not want to meet no matter what. Without these people, eHarmony would likely go out of business.
If you decide to pay for a membership, be prepared for meeting many unattractive people who refuse to post photos before meeting. Be sure to meet for coffee or water so you don't go broke on bad dates.