Clover seed used to be mixed with grass seed for lawn planting up until chemical weed controls became popular. The chemicals kill the clover along with all the other non grass weeds. Several of my really old lawn and gardening books talk about the amount of clover to seed with.
I love clover. It's so soft underfoot and takes mowing so well. Stays green longer than the grass in the summer, too. I'd love a small outdoor reading area with just clover.
My birds love the clover and dandelions. After the rain comes back, I have some to plant just for them.