Chapbooks are much less expensive to produce than full-length collections. Many poets who have gone on to publish full-length collections began by publishing chapbooks. In fact, many small presses are more willing to publish a chapbook by a lesser known poet because they don't require as much money upfront and, therefore, don't need to make as much money in return. Also, chapbooks are great to hand out at readings to help poets develop name recognition within the poetry community. The hardest task a poet has, besides writing the poem, is finding the right market for their poetry.
Diligence is the key to being published whether on the Internet or in print.
I view poetry contests as another market for publishing your work. Most contests, besides offering a monetary prize, usually include publication of the winning poems in the journal that is sponsoring the contest. Also, first-book competitions are the best way for beginning poets to get a collection published. First-book competitions want poets who have never published a book before. Although, numerous publication credits in journals indicate that a poet is ready to make the step to book publication.