I've been around the block a few times, so have no illusions. Most people on the Gaydars Squirts, and Scruffs of this world are there for a quick shag at best, or a sneering browse at worst. So I have come to a few, perhaps jaded, conclusions.
If you are more than 40, beware; there's no fool like an old fool. Those winking twinks, gagging for your favours, are seldom what they seem.
If you are looking for a long term relationship, skip the sites. Chat to people at the bus stop, corner shop, or join a club. If you share an activity (stamp collecting, motorbike racing, scuba diving etc.) you are more likely to click.
95% of datesite users cannot accommodate. Why? Partners? Wives? Lodgers? Stranger Danger? So, if you are one of those who can you will become instantly attractive to others. Beware; inviting others (unknown others) into your house is a risk. Do some research before inviting. Perhaps meet them in a public place first. Take a photo of them, their car and anything else that could identify them later if things turn nasty. If you do let them into your place, make it tidy. Hide all the expensive stuff away. Remove temptation of that sort.
Be realistic. There will be some people who mess around. They may agree to meet, but make an excuse just before the time. Work, the wife, family crisis, sick dog. The list is endless. So you reschedule only to discover that the day before they caught the cold from hell. So it goes. Be kind, some of it may be true, but only allow three no shows before you quit that avenue. If they just don't turn up, leaving you high and dry, then call it a day just then. There is no excuse for such bad manners.
So, in conclusion, the answer to the question, Dating websites? Yay or nay? I have to say yay, but don't expect much more than an occasional no strings shag and be prepared for some odd timewasting folk.