I first bought one of these stretchy black skirts made of jersey material about 4 years ago when they were first creeping into fashion. It was perfect - a mini-skirt that you could just slip on and all for £3.99!
I must own about 10 different tube skirts, most from H&M. I have different colours to suit the rest of my clothes; H&M changes its colours and patterns with the season - each store usually has about 8 at any one time.

They are so cheap to buy because they are made fairly cheaply - I wore one probably 2 or 3 times a week for a year and the hem did start unstitch, but in fairness I did wear it A LOT. Looking back I'm surprised at how long it actually lasted. I even owned a more expensive one from Miss Selfridge that had full on holes in multiple places so H&M was actually in my opinion better quality.

They are a little bit see through. I'm not sure how confident I would be wearing it with bare legs during the day because I'm pretty sure you'd be able to see right through it. They are mini and I feel for a day look they need black tights or leggings to be appropriate (unless maybe it was a very warm day and everybody was dressing practically naked!). They don't tend to ride up as much as more rigid skirts - I don't find myself pulling them down all the time. But the thing I love about these skirts are that they can be worn during the day in summer and in winter with thick tights and a jumper, but are also perfect for a night out with bare legs, heels and a strappy top. In my opinion, these tube skirts are the most essential wardrobe basic.

The proper bodycon skirts with a zip are better quality and more heavy duty, but they are much more expensive and I don't think they are as comfortable. The tube skirts are stretchy with no zip which means there's nothing to dig in and they don't feel too tight or constricting because they stretch with you. I have found they come up a bit too high in my waist which can be great for wearing with a top tucked in and a waist belt, but underneath a top I find it catches on my belly-button piercing. Also if you're wearing a white t-shirt you'll probably be able to see the skirt up to your ribs which might look a bit odd!
Overall, I could never not have at least one of these in my wardrobe. I love them to bits and I personally think they go with almost every outfit!