Add Zulip cons

diff --git a/blueprint/instant-messaging.md b/blueprint/instant-messaging.md
index 7262f0f6dfabb89191664ca9451390788b631e3f..98bebe38304f5c230b499199a339b8133103000b 100644 (file)
--- a/blueprint/instant-messaging.md
+++ b/blueprint/instant-messaging.md
@@ -24,3 +24,9 @@ Zulip could be a great option because:
 * You can use the web interface, terminal interface, email interface.
 * Third-party clients should be allowed?
 * You can switch from their free/paid services to self-hosted plans easily.
+
+The major cons are:
+
+* Self-hosted service likely requires a dedicated host, esp. if you want email integration.
+* Managed service mentions that communities can opt-in to free upgrade to the plan that includes unlimited archives and public access[^1].
+  However, managed service + custom domain costs a lot of money and is not included in free upgrades.