Venture capital is actually a ruthlessly competitive business, so sometimes you can skip the seed part if you have a hot deal or a VC has a good gut for the market. In my opinion, this is a bad move. You can get excellent terms on a seed deal if you are in a position to be able to skip it, and everyone is happier and better off that you prove out the product before scaling up the business. The point of all of this is to build a viable business, not to raise venture capital.
There are always exceptions to the rule, but you are much better off just following the standard VC process. It is much more predictable, a lot less stressful, and you don't waste a bunch of time in meetings that are not going to go anywhere.