What I love about anthologies is that a quick shorter story often allows readers to have a taste for a writer's style and voice. I've discovered some great authors by reading anthology books. The majority of anthology books are put out with certain themes in the stories.
Themes can be anything from military, to creatures, or perhaps even seasons. These themed anthologies present a great opportunity for writers to reach more readers through shorter works. Shorter stories are definitely easier for me to write, so I'm always on the lookout for interesting anthologies where I might submit and allow readers to have a taste of my writing style.
Most e-publishers will put out anthology collections and do have submissions for these on a frequent basis. The most popular anthologies are often holiday themed, so if you have a Christmas or Valentines story that is ready for publication, consider an anthology.
The pay for contributing to an anthology is typically much smaller, but the upside is that it will often give your backlist a bump. Also, you never know what larger and more widely read authors you might be sharing the anthology with which can increase sales.
Should you contribute to an anthology if there is 'no pay' involved? My answer would be no, simply because I believe an author's time and work are of value. There are plenty of romance publishers who will pay a small percentage and are more worthy of your good story. Don't sell yourself short.
I hope this has given you budding authors something to consider on your path to publication. Good luck to you all!