Why did Shakespeare use the sonnet cycle form?
Shakespeare loves great work and full length play,that's why he liked collection form of the sonnets. Through this work,he got a great applause.
Although they were first published under the title of Shake-speares Sonnets in 1609, we know that at least some of sonnets in that collection were written at least ten years earlier. Two of them, Sonnets 138 and 144 from the so-called "dark lady" cycle, appeared in a miscellaneous collection called The Passionate Pilgrim which must have been written before 1598. Most scholars assign the sonnets an early date in Shakespeare's career; stylistic evidence suggests that they were written in 1592 and/or 1593. A year earlier in 1591, Philip Sidney's sonnet cycle Astrophel and Stella was published posthumously (Sidney died in 1586; Astrophel and Stella may have been written as early as 1582). The appearance of Sidney's work proved to be an immediate success with English readers. Shakespeare was certainly aware of market demand for the sonnet cycle and was probably drawn to the genre more by commercial than by artistic considerations. Nevertheless, he did not publish his sonnets in collected form; nor did he authorize their publication in 1609. By 1592, however, Shakespeare's career as a playwright was beginning to make headway, the theater being a much more lucrative medium than poetry. As important, the sonnet cycle fad proved short-lived. By the time that they were published in collected form, English readers had tired of the form.