I tried it and met a few nice people. Mostly not. Both my husband and I were trying eHarmony when a mutual friend introduced us. eHarmony never once suggested us as potential partners but we are the best of friends and very much in love.
Meeting anyone new has its drawbacks. Just because you meet in the grocery store, doesn't mean he is clean, honest and trustworthy. Go in to it to have fun, meet people and have no expectations! Let life surprise you.