People will think you are not serious
Most dating sites will require you to register in some way before being allowed to run full searches. This leads some people to set up a profile just so they can have a quick look around. If you’re just having a look and are not necessarily interested in making contact just yet, you may not want to go through the trouble of finding a good photo and uploading it. However, if your profile contains little information and you do not upload a picture, people may assume you are one of those people who are just looking around, even if you are more serious. If the person looking at your profile is serious about finding a partner or a date online, they may not bother contacting you at all because he/she may think it would be a waste of time. It’s worth keeping in mind that even if you are only having a look, you will get a much better response if you upload a photo.
People will think you have something to hide
While there are some perfectly innocent reasons why people may not want to upload a picture (as stated above) it’s also quite common for the reasons to be less than innocent. For example, people who are married or in a relationship often turn to the Internet in order to find people to cheat with. For obvious reasons, such people do not want their picture to be publicly available. Many online dating guides advise their readers to watch out for profiles without pictures exactly for this reason. Putting up a picture shows you have nothing to hide.
People will think you are hideously ugly
Harsh but true. While different people have different tastes, if you deny them of the chance to see what you look like, they may end up assuming the worst. Even if you are insecure about your looks, you may be exactly what the other person is looking for. Why not let the other person decide for him or herself?
People will not see you come up in the search at all
For the reasons detailed above, many people prefer not to be contact and be contacted by people who have not uploaded a picture to the site. Some dating sites offer their user the choice of specifying this when searching for people. This means your profile will not even show up in their searches, even though you fit their other search criteria perfectly.