--- title: Reach and impression estimates slug: reach-and-impression-estimates description: At Roster, we want brands to have the most accurate and reliable metrics possible when measuring ambassador and creator performance. docTags: createdAt: 2025-09-24T20:59:26.843Z --- ## How Roster Estimates Reach and Impressions At Roster, we want brands to have the most accurate and reliable metrics possible when measuring ambassador and creator performance. Our first priority is always to use the actual data provided directly by the social networks (Instagram, TikTok, YouTube, Facebook). However, the networks don’t always make every metric available to us. For example: - Instagram’s API only provides reach and impressions when an ambassador has connected their account. - TikTok provides impressions (views) but not reach. - Some networks don’t expose post-level metrics at all (e.g. Facebook posts on personal profiles.) When this happens, Roster fills in the gaps with estimates based on real-world data for the given post type and follower size. ## How Estimates Are Calculated Originally, Roster filled in missing reach by using a simple rule of thumb: 15% of a poster’s follower count. This was a good average across our dataset at the time. As we prepared to introduce Earned Media Value (EMV), we needed a more accurate way to estimate both reach and impressions (since EMV is based on impressions + engagement). To improve accuracy, we analyzed of posts where networks provided follower count, reach, and impressions. From this, we built typical ratios by post type and follower size: - **Post type** (e.g., Instagram post, Instagram reel, etc.) - **Follower size** (e.g., Pico \<1k, Nano 1k–10k, Micro 10k–100k, etc.) These ratios let us estimate missing data with more realistic defaults. Below are the impressions and reach ratios we use to estimate missing values for Instagram and Facebook posts. | Post Type | Follower Size | Impressions per Follower | Reach per Follower | Impressions per Reach | | ------------- | -------------------- | ------------------------ | ------------------ | --------------------- | | IG / FB Posts | Pico (\<1k) | 76% | 24% | 3.12 | | IG / FB Posts | Nano (1k–10k) | 36% | 13% | 2.88 | | IG / FB Posts | Micro (10k–100k) | 18% | 6% | 2.89 | | IG / FB Posts | Mid-tier (100k–500k) | 11% | 3% | 2.53 | | IG / FB Posts | Mega (500k+) | 5% | 3% | 1.94 | | IG / FB Reels | Pico (\<1k) | 107% | 75% | 1.34 | | IG / FB Reels | Nano (1k–10k) | 40% | 27% | 1.43 | | IG / FB Reels | Micro (10k–100k) | 13% | 8% | 1.43 | | IG / FB Reels | Mid-tier (100k–500k) | 10% | 6% | 1.42 | | IG / FB Reels | Mega (500k+) | 9% | 6% | 1.62 | | IG Stories | Pico (\<1k) | 16% | 14% | 1.16 | | IG Stories | Nano (1k–10k) | 6% | 5% | 1.15 | | IG Stories | Micro (10k–100k) | 1% | 1% | 1.12 | | IG Stories | Mid-tier (100k–500k) | 1% | 1% | 1.10 | | IG Stories | Mega (500k+) | 1% | 1% | 1.05 | TikTok does not report a "unique reach" metric like Instagram or Facebook. Instead, TikTok provides views (impressions). In Roster, we set a TikTok's reach to its impression so that your dashboards and campaign reports remain consistent. ## Why This Matters - **Better accuracy than one-size-fits-all.** Instead of assuming something like “15% of followers reached” for every account, we recognize that Pico accounts behave differently than Micro or Mid-tier accounts, and that Reels behave differently than Posts. - **Transparency.** For each bucket and post type, we publish not only the median values but also the middle 50% range (interquartile range) so you can see the typical spread of outcomes. - **Continuous improvement.** As more ambassadors connect their accounts and we collect more verified data, we update our estimator ratios to reflect the latest reality. ## How it Works When Roster captures a post that mentions your brand, we make every effort to get the real reach and impressions data directly from the social network. If we are unable to get these metrics from the network, we will estimate the missing metrics based on the post type and follower size. For example, if a Instagram profile with 3,000 followers mentions your brand in a reel, but the person who owns that Instagram profile hasn't connected their Instagram account to their Roster ambassador profile, then Roster will use 41% of the Instagram profile's follower size as the reel's impressions estimate (1,230) and 28% of the profile's follower size as the reach estimate (840). ## What This Means for You - Whenever possible, Roster displays the *actual* impressions and reach provided by the network. - If the network doesn’t provide a reach and/or impressions metric, we fill in the blanks using the table above so your reporting remains consistent. - Tooltips and help text in Roster will let you know when a number is an estimate and what assumptions it’s based on. ## Summary Roster’s goal is to balance accuracy (using network-provided data when available) with completeness (estimating responsibly when data is missing). Our estimator is powered by thousands of real ambassador posts and is continually updated to ensure your reporting stays relevant and reliable.