1. People posted a lot of comments on my blog.

Both sentences are grammatically correct, but there is a slight difference in meaning between "posted" and "uploaded" when used in the context of blog comments.

1. "People posted a lot of comments on my blog." In this sentence, "posted" implies that people wrote and published their comments on your blog. It suggests that users manually typed their comments directly into the comment section on your blog.

2. "People uploaded a lot of comments on my blog." In this sentence, "uploaded" implies that people submitted their comments by uploading a file or document onto your blog. This might refer to a situation where users could attach files or documents as comments to your blog post.

The choice between "posted" and "uploaded" depends on the specific functionality of your blog's comment section. If your blog allows users to directly type and publish their comments, then "posted" would be more appropriate. However, if your blog allows users to attach files or documents as comments, then "uploaded" would be more appropriate.