When you create a personal profile, you can choose the type of profile you want to create: searchable or not searchable.
Searchable profiles appear in the search results for millions of singles to see. If you create a searchable profile, you have a better experience because you'll have more interaction.
Not searchable profiles do not appear in the search results. However, if you create this type of profile, you can attach it to messages you send when replying to other profiles. This is helpful because many people aren't entirely comfortable with putting their profile in front of millions of people, but they want to have a profile to show to the people they are interested in.
Hint: If you're going on vacation and you won't be able to answer replies to your profile, change your Mailbox Status to unavailable from the "Going out of town or temporarily unavailable?" link on the Mailbox Home page