Add new links to FAQ and comparison

Also, update FAQs a bit. (Needs a more thorough update, though.)

content/docs/introduction/comparison.md

@@ -104,12 +104,15 @@ https://github.com/influxdb/influxdb/issues/582).
 
 Still, InfluxDB is better geared towards the following use cases:
 
-   * storing all **individual** events, not just time series of values
-      * e.g. storing every HTTP request with full metadata *vs.* storing the cumulative count of HTTP requests for certain dimensions
-   * storing time series with completely unbounded dimensionality
-      * e.g. storing user IDs or email addresses in the key-value metadata *vs.*
-        storing bounded dimensionality like the HTTP method, HTTP handler and
-        instance ID
+   * Storing all **individual** events, not just time series of values.
+      * E.g. storing every HTTP request with full metadata *vs.* storing the
+        cumulative count of HTTP requests for certain dimensions.
+	  * [Logs and Metrics and Graphs, Oh My!](https://blog.raintank.io/logs-and-metrics-and-graphs-oh-my/)
+        describes the difference between event logging and metrics recording.
+   * Storing time series with completely unbounded dimensionality.
+      * E.g. storing user IDs or email addresses in the key-value metadata
+        *vs.* storing bounded dimensionality like the HTTP method, HTTP handler
+        and instance ID.
 
 There are other storage features, such as downsampling, which InfluxDB supports
 and Prometheus does not yet.

content/docs/introduction/faq.md

@@ -26,6 +26,12 @@ Identical alerts will be deduplicated by the [Alertmanager](https://github.com/p
 
 The Alertmanager cannot currently be made highly available, but this is a goal.
 
+### I was told Prometheus “doesn't scale”.
+
+There are in fact various ways to scale and federate
+Prometheus. Read [Scaling and Federating Prometheus](http://www.robustperception.io/scaling-and-federating-prometheus/)
+on the Robust Perception blog to get started.
+
 ### What language is Prometheus written in?
 
 Most Prometheus components are written in Go. Some are also written in Java and Ruby.
@@ -57,6 +63,18 @@ blog post by Brian Brazil goes into more detail.
 
 For cases where you must push, we offer the [Pushgateway](/docs/instrumenting/pushing/).
 
+### How to feed logs into Prometheus?
+
+Short answer: Don't! Use something like the ELK stack instead.
+
+Longer answer: Prometheus is system to collect and process metrics, not an
+event logging system. The Raintank blog post
+[Logs and Metrics and Graphs, Oh My!](https://blog.raintank.io/logs-and-metrics-and-graphs-oh-my/)
+provides more details about the differences between logs and metrics.
+
+If you want to extract Prometheus metrics from application logs, Google's
+[mtail](https://github.com/google/mtail) might be helpful.
+
 ### Who wrote Prometheus?
 
 Prometheus was initially started privately by