You may have often enjoyed using free WordPress plugins developed by various authors. There are chances that you may have also asked for support for issues related to a few of those plugins and may have been miffed to receive a delayed solution to your problems or no support at all.
However, rather than rush to blame the author of that free plugin, it would be wise to consider a few facts before actually venting your anger at the author. There are roughly around 15,000 downloads of a WordPress plugin every day that translates to around one plugin download at every 6 seconds. There are quite a few plugins that have exceeded over 5 million downloads.
Depending on the plugin, there are bound to be some issues related to compatibility, speed, unresolved bugs, etc., that may need to be solved as they begin cropping up. You must understand that authors that offer free plugins often do so during their free time, which is anyway limited.
An author with decent number of downloads may receive a lot of feedback and may not have time to go through all of them at one go. A few million downloads may result in thousands of queries through not only support forums of the WordPress plugin directory, but also through emails. Unfortunately most users do not understand that most of the issues could have been sorted out had they viewed the Frequently Asked Questions (FAQ) section in detail or followed the installation instructions properly or read the help or readme file.
Most users also fail to implement a simple search to get answers to their queries instantly. Many users do post problems and solutions online that can help you get an instant solution to a bug or compatibility issues. Anyway, a simple solution related to compatibility is to try to disable one plugin after the other to locate the plugin that clashes with your downloaded free plugin.
You must finally understand that each author of a free WordPress plugin is after all a human being with a hectic work schedule, a family, and with feelings too. You must appreciate the efforts put in by the author and provide both good and bad feedback in a positive way.