Social media has been gradually emerging at the forefront of election campaigning, and this transition has been further accelerated with the ongoing pandemic. In this extended abstract, we describe a mixed-methods approach to study paid election campaigning by contesting candidates, as well as parties, on Facebook. We have employed this approach to analyze online campaigning during two major Indian state legislative assembly elections - Bihar (November 2020) and West Bengal (May 2021). This analysis provides insights on the effectiveness of online campaigning strategies of contesting candidates and parties, while also making the discourse more accessible to the voters. We also compare this discourse with the tweets by the same users to study the differences between paid and unpaid online campaigning.