Why

You haven't mentioned a team, a second agent, or a volume number — which means you're likely solo and fielding listing inquiries yourself. Internet listings (Zillow, Realtor.com, or equivalent portals) usually push leads via email or SMS, so the data already lands somewhere. The problem is almost certainly response speed and follow-up consistency, not storage.

What you actually need

1. Google Sheets, free — one tab, seven columns: name, contact, source listing, date in, last contact, next action, status. Every lead from every portal goes here within 24 hours.
2. Zapier or Make, free tier — auto-post each new portal lead notification into a single Gmail label or Slack channel so nothing gets buried in a cluttered inbox.
3. A habit — reply within 5 minutes of receiving a listing inquiry — set your phone to alert on that Gmail label or portal app; internet listing leads go cold faster than almost any other lead type.

Do this today

Open Google Sheets right now, create a new sheet called "Leads," and paste in every listing inquiry you've received in the last 30 days with their contact info and the listing they asked about. You'll immediately see who never got a follow-up — and you can message them today.

What to ignore

You do not need HubSpot Sales Hub, Salesforce, or Pipedrive. Any sales rep pushing you toward a $50–$100/month CRM subscription for a solo agent pulling leads from internet listings is selling you overhead, not leverage. The portals themselves (Zillow Premier Agent, etc.) already have basic lead tracking built in — use that before paying for anything else.

What doing nothing costs you

Internet listing leads have some of the highest slippage rates in any industry — agents who respond after 5 minutes convert dramatically less than those who respond immediately. Without a system, you have no visibility into who was never followed up, which means lost commissions compound silently every month.

When to revisit this

When you're managing more than 40 active leads simultaneously or you bring on an assistant who needs to see the same pipeline you do.