Gazebos are a brilliant way of providing shelter if you don't want to put up an awning - perhaps you are only staying for a few days or the weather isn't bad enough to have to put up an awning.
There are many positive points about buying one. They can be lightweight and small enough to stow in your caravan. They can also be bought very cheaply or, if you need a better quality one, you can pay much more. The choice is down to you and your requirements but remember, you only get what you pay for!
They need to be securely tied down with guy ropes and maybe even storm straps in bad weather. A sudden gust of wind will easily blow one away if it isn't secured down sufficiently. Not all will come supplied with enough pegs and guy ropes so you may have to purchase extra.
You can buy a Pop Up Gazebo or a Folding Gazebo - it all depends on what you want to use it for and your budget. Obviously a more expensive one will have tougher fabric and more velcro straps to attach the cover to the frame.
Some even come with sides which you can attach if required, which make it a very versatile piece of kit.
We have a basic slot-together one which we have used in the past for cooking under in the rain! We now use it at home and leave it erected in the garden for the summer months. Cheap gazebos can be left out in all weathers (as long as they are securely tied down) as it doesn't matter if they do disintegrate. See if you can buy a new one at the end of the summer when all the sales are on!
If you don't want to splash out on an awning, a gazebo is a good compromise and can be used for other things, e.g. garden parties, fetes, etc. An extremely good piece of kit as long as you securely tie it down!